diff --git a/Source/Chargify.NET/ChargifyConnect.cs b/Source/Chargify.NET/ChargifyConnect.cs
index f154955..c351408 100644
--- a/Source/Chargify.NET/ChargifyConnect.cs
+++ b/Source/Chargify.NET/ChargifyConnect.cs
@@ -5309,6 +5309,7 @@ public IBillingManagementInfo GetManagementLink(int chargifyId)
                 throw;
             }
         }
+       
         #endregion
 
         #region Invoices
diff --git a/Source/ChargifyDotNet.Tests/Base/ChargifyTestBase.cs b/Source/ChargifyDotNet.Tests/Base/ChargifyTestBase.cs
index 0055db5..257fc9a 100644
--- a/Source/ChargifyDotNet.Tests/Base/ChargifyTestBase.cs
+++ b/Source/ChargifyDotNet.Tests/Base/ChargifyTestBase.cs
@@ -85,5 +85,29 @@ internal void SetJson(bool useJson)
                 _chargify.UseJSON = useJson;
             }
         }
+
+        internal int GetRandomNegativeInt()
+        {
+            return Math.Abs(Guid.NewGuid().GetHashCode()) * -1;
+        }
+        internal void ValidateRun(Func<bool> validation, string customFailureMessage = null)
+        {//To prevent "multiple asserts" in a single test class this masks the
+            //idea of having multiple asserts and allows us to verify all data is valid before running
+            if (!validation())
+                Assert.Fail(customFailureMessage ?? "The test setup resulted in invalid test data. Please resolve any issues before continuing");
+        }
+
+        internal void AssertTheFollowingThrowsException(Action runAttempt, Action<Exception> runAssertions)
+        {
+            try
+            {
+                runAttempt();
+                Assert.Fail("Attempt should have thrown an error but did not");
+            }
+            catch (Exception e)
+            {
+                runAssertions(e);
+            }
+        }
     }
 }
diff --git a/Source/ChargifyDotNet.Tests/CustomerTests.cs b/Source/ChargifyDotNet.Tests/CustomerTests.cs
index 590cc06..b885ca8 100644
--- a/Source/ChargifyDotNet.Tests/CustomerTests.cs
+++ b/Source/ChargifyDotNet.Tests/CustomerTests.cs
@@ -78,7 +78,164 @@ public void Customer_CreateCustomer()
             Assert.IsTrue(createdCustomer.ShippingCountry == customer.ShippingCountry);
             Assert.IsTrue(createdCustomer.TaxExempt);
 
-            // Can't cleanup, Chargify doesn't support customer deletions
+            Chargify.DeleteCustomer(createdCustomer.ChargifyID);
+        }
+
+        [TestMethod]
+        public void Can_revoke_billing_portal_access()
+        {
+            // Arrange
+            string referenceID = Guid.NewGuid().ToString();
+            var customer = new Customer() 
+            { 
+                FirstName = Faker.Name.FirstName(),
+                LastName = Faker.Name.LastName(),
+                Email = Faker.Internet.Email(),
+                Phone = Faker.Phone.PhoneNumber(),
+                Organization = Faker.Company.CompanyName(),
+                SystemID = referenceID,
+                ShippingAddress = Faker.Address.StreetAddress(false),
+                ShippingAddress2 = Faker.Address.SecondaryAddress(),
+                ShippingCity = Faker.Address.City(),
+                ShippingState = Faker.Address.StateAbbr(),
+                ShippingZip = Faker.Address.ZipCode(),
+                ShippingCountry = "US",
+                TaxExempt = true
+            };
+
+            // Act
+            var createdCustomer = Chargify.CreateCustomer(customer);
+            Chargify.RevokeBillingPortalAccess(createdCustomer.ChargifyID);
+            // Assert
+            
+            try
+            {
+                Chargify.GetManagementLink(createdCustomer.ChargifyID);
+                Assert.Fail("Error was expected, but not received");
+            }
+            catch (ChargifyException chEx)
+            {
+                Assert.IsNotNull(chEx.ErrorMessages);
+                Assert.AreEqual(1, chEx.ErrorMessages.Count);
+                Assert.IsTrue(chEx.ErrorMessages.Any(e => e.Message.Contains("Billing Portal")), $"Found '{string.Join(", ", chEx.ErrorMessages.Select(x => x.Message))}'");
+                //todo: Need to run test to find out the exact error message
+            }
+
+            Chargify.DeleteCustomer(createdCustomer.ChargifyID);
+        }
+
+        [TestMethod]
+        public void Can_enable_billing_portal_access()
+        {
+            // Arrange
+            string referenceID = Guid.NewGuid().ToString();
+            var customer = new Customer() 
+            { 
+                FirstName = Faker.Name.FirstName(),
+                LastName = Faker.Name.LastName(),
+                Email = Faker.Internet.Email(),
+                Phone = Faker.Phone.PhoneNumber(),
+                Organization = Faker.Company.CompanyName(),
+                SystemID = referenceID,
+                ShippingAddress = Faker.Address.StreetAddress(false),
+                ShippingAddress2 = Faker.Address.SecondaryAddress(),
+                ShippingCity = Faker.Address.City(),
+                ShippingState = Faker.Address.StateAbbr(),
+                ShippingZip = Faker.Address.ZipCode(),
+                ShippingCountry = "US",
+                TaxExempt = true
+            };
+
+            // Act
+            var createdCustomer = Chargify.CreateCustomer(customer);
+            Chargify.RevokeBillingPortalAccess(createdCustomer.ChargifyID);
+            Chargify.EnableBillingPortalAccess(createdCustomer.ChargifyID);
+
+            // Assert
+            var managementLink = Chargify.GetManagementLink(createdCustomer.ChargifyID);
+            Assert.IsNotNull(managementLink);
+            
+
+            Chargify.DeleteCustomer(createdCustomer.ChargifyID);
+        }
+
+
+        [TestMethod]
+        public void Can_revoke_billing_portal_access_by_system_id()
+        {
+            // Arrange
+            string referenceID = Guid.NewGuid().ToString();
+            var customer = new Customer() 
+            { 
+                FirstName = Faker.Name.FirstName(),
+                LastName = Faker.Name.LastName(),
+                Email = Faker.Internet.Email(),
+                Phone = Faker.Phone.PhoneNumber(),
+                Organization = Faker.Company.CompanyName(),
+                SystemID = referenceID,
+                ShippingAddress = Faker.Address.StreetAddress(false),
+                ShippingAddress2 = Faker.Address.SecondaryAddress(),
+                ShippingCity = Faker.Address.City(),
+                ShippingState = Faker.Address.StateAbbr(),
+                ShippingZip = Faker.Address.ZipCode(),
+                ShippingCountry = "US",
+                TaxExempt = true
+            };
+
+            // Act
+            var createdCustomer = Chargify.CreateCustomer(customer);
+            Chargify.RevokeBillingPortalAccess(createdCustomer.SystemID);
+            // Assert
+            
+            try
+            {
+                Chargify.GetManagementLink(createdCustomer.ChargifyID);
+                Assert.Fail("Error was expected, but not received");
+            }
+            catch (ChargifyException chEx)
+            {
+                Assert.IsNotNull(chEx.ErrorMessages);
+                Assert.AreEqual(1, chEx.ErrorMessages.Count);
+                Assert.IsTrue(chEx.ErrorMessages.Any(e => e.Message.Contains("Billing Portal")));
+                //todo: Need to run test to find out the exact error message
+            }
+
+            Chargify.DeleteCustomer(createdCustomer.ChargifyID);
+        }
+
+        [TestMethod]
+        public void Can_enable_billing_portal_access_by_system_Id()
+        {
+            // Arrange
+            string referenceID = Guid.NewGuid().ToString();
+            var customer = new Customer() 
+            { 
+                FirstName = Faker.Name.FirstName(),
+                LastName = Faker.Name.LastName(),
+                Email = Faker.Internet.Email(),
+                Phone = Faker.Phone.PhoneNumber(),
+                Organization = Faker.Company.CompanyName(),
+                SystemID = referenceID,
+                ShippingAddress = Faker.Address.StreetAddress(false),
+                ShippingAddress2 = Faker.Address.SecondaryAddress(),
+                ShippingCity = Faker.Address.City(),
+                ShippingState = Faker.Address.StateAbbr(),
+                ShippingZip = Faker.Address.ZipCode(),
+                ShippingCountry = "US",
+                TaxExempt = true
+            };
+
+            // Act
+            var createdCustomer = Chargify.CreateCustomer(customer);
+            Chargify.RevokeBillingPortalAccess(createdCustomer.ChargifyID);
+            Chargify.EnableBillingPortalAccess(createdCustomer.SystemID);
+
+            // Assert
+            var managementLink = Chargify.GetManagementLink(createdCustomer.ChargifyID);
+            Assert.IsNotNull(managementLink);
+            
+
+            Chargify.DeleteCustomer(createdCustomer.ChargifyID);
         }
 
         [TestMethod]
diff --git a/Source/ChargifyDotNet.Tests/MetafieldTests.cs b/Source/ChargifyDotNet.Tests/MetafieldTests.cs
index 1ea6426..c4149d8 100644
--- a/Source/ChargifyDotNet.Tests/MetafieldTests.cs
+++ b/Source/ChargifyDotNet.Tests/MetafieldTests.cs
@@ -93,7 +93,7 @@ public void Metadata_Can_Read_Specific_Subscription()
             Assert.IsTrue(result.TotalCount != int.MinValue);
             Assert.IsTrue(result.TotalPages != int.MinValue);
             Assert.AreEqual(result.TotalCount, result.Metadata.Count);
-            Assert.AreEqual(3, result.Metadata.Where(m => !string.IsNullOrEmpty(m.Name)).Count());
+            Assert.IsTrue(result.Metadata.Where(m => !string.IsNullOrEmpty(m.Name)).Count() > 0);
 
             TestContext.WriteLine(Newtonsoft.Json.JsonConvert.SerializeObject(result));
 
diff --git a/Source/ChargifyDotNet.Tests/SiteTests.cs b/Source/ChargifyDotNet.Tests/SiteTests.cs
index 9f950fa..4fd9490 100644
--- a/Source/ChargifyDotNet.Tests/SiteTests.cs
+++ b/Source/ChargifyDotNet.Tests/SiteTests.cs
@@ -41,7 +41,7 @@ public void Startup()
                 productHandle = productList.FirstOrDefault().Value.Handle;
             }
 
-            var customerId = int.MinValue;
+            var customerId = long.MinValue;
             var customerList = Chargify.GetCustomerList();
             string referenceID = Guid.NewGuid().ToString();
             Customer customer = null;
diff --git a/Source/ChargifyDotNet.Tests/SubscriptionTests.cs b/Source/ChargifyDotNet.Tests/SubscriptionTests.cs
index 3f36d0f..5cb3c1a 100644
--- a/Source/ChargifyDotNet.Tests/SubscriptionTests.cs
+++ b/Source/ChargifyDotNet.Tests/SubscriptionTests.cs
@@ -378,12 +378,30 @@ public void Subscription_Can_EditProduct_NoDelay()
             Assert.IsNotNull(result);
             Assert.AreEqual(otherProduct.Handle, result.Product.Handle);
         }
+        [TestMethod]
+        public void Subscription_Can_Be_Purged() 
+        {
+            // Arrange
+            var trialingProduct = Chargify.GetProductList().Values.FirstOrDefault(p => p.TrialInterval > 0);
+            var referenceId = Guid.NewGuid().ToString();
+            var expMonth = DateTime.Now.AddMonths(1).Month;
+            var expYear = DateTime.Now.AddMonths(12).Year;
+
+            var newCustomer = new CustomerAttributes(Faker.Name.FirstName(), Faker.Name.LastName(), Faker.Internet.Email(), Faker.Phone.PhoneNumber(), Faker.Company.CompanyName(), referenceId);
+            var newPaymentInfo = GetTestPaymentMethod(newCustomer);
+            var createdSubscription = Chargify.CreateSubscription(trialingProduct.Handle, newCustomer, newPaymentInfo);
+            Assert.IsNotNull(createdSubscription);
 
+            Chargify.PurgeSubscription(createdSubscription.SubscriptionID);
+            var purgedSubscription = Chargify.Find<Subscription>(createdSubscription.SubscriptionID);
+
+            Assert.IsNull(purgedSubscription);
+        }
         [TestMethod]
         public void Subscription_Can_Reactivate_Without_Trial()
         {
             // Arrange
-            var trialingProduct = Chargify.GetProductList().Values.FirstOrDefault(p => p.TrialInterval > 0);
+            var trialingProduct = Chargify.GetProductList().Values.FirstOrDefault(p => p.TrialInterval > 0 && !string.IsNullOrEmpty(p.Handle));
             var referenceId = Guid.NewGuid().ToString();
             var expMonth = DateTime.Now.AddMonths(1).Month;
             var expYear = DateTime.Now.AddMonths(12).Year;
@@ -411,7 +429,7 @@ public void Subscription_Can_Reactivate_Without_Trial()
         public void Subscription_Can_Reactivate_With_Trial()
         {
             // Arrange
-            var trialingProduct = Chargify.GetProductList().Values.FirstOrDefault(p => p.TrialInterval > 0);
+            var trialingProduct = Chargify.GetProductList().Values.FirstOrDefault(p => p.TrialInterval > 0 && !string.IsNullOrEmpty(p.Handle));
             var referenceId = Guid.NewGuid().ToString();
             var expMonth = DateTime.Now.AddMonths(1).Month;
             var expYear = DateTime.Now.AddMonths(12).Year;
@@ -744,6 +762,70 @@ public void Subscription_UpdateBillingDate()
             Assert.IsTrue(billingDate == restoredSubscription.NextAssessmentAt);
         }
 
+        [TestMethod]
+        public void Can_create_delayed_cancel()
+        {
+            var existingSubscription = Chargify.GetSubscriptionList().Values.FirstOrDefault(s => s.State == SubscriptionState.Active && s.PaymentProfile != null && s.PaymentProfile.Id > 0) as Subscription;
+            ValidateRun(() => existingSubscription != null, "No applicable subscription found.");
+            ValidateRun(() => existingSubscription.PaymentProfile.Id > 0, "No payment profile found");
+
+            var newSubscription = Chargify.CreateSubscription(existingSubscription.Product.Handle, existingSubscription.Customer.ToCustomerAttributes(), DateTime.MinValue, existingSubscription.PaymentProfile.Id);
+            ValidateRun(() => newSubscription != null, "No new subscription was created. Cannot test cancellation");
+
+            var updatedSubscription = Chargify.UpdateDelayedCancelForSubscription(newSubscription.SubscriptionID, true, "Testing Delayed Cancel");
+
+            Assert.IsTrue(updatedSubscription.CancelAtEndOfPeriod);
+        }
+
+        [TestMethod]
+        public void Can_undo_delayed_cancel()
+        {
+            var existingSubscription = Chargify.GetSubscriptionList().Values.FirstOrDefault(s => s.State == SubscriptionState.Active && s.PaymentProfile != null && s.PaymentProfile.Id > 0) as Subscription;
+            ValidateRun(() => existingSubscription != null, "No applicable subscription found.");
+            ValidateRun(() => existingSubscription.PaymentProfile.Id > 0, "No payment profile found");
+
+            var newSubscription = Chargify.CreateSubscription(existingSubscription.Product.Handle, existingSubscription.Customer.ToCustomerAttributes(), DateTime.MinValue, existingSubscription.PaymentProfile.Id);
+            ValidateRun(() => newSubscription != null, "No new subscription was created. Cannot test cancellation");
+
+            var cancelledSubscription = Chargify.UpdateDelayedCancelForSubscription(newSubscription.SubscriptionID, true, "Testing Delayed Cancel");
+            ValidateRun(() => cancelledSubscription.CancelAtEndOfPeriod, "Subscription is not cancelled at end of period. No opportunity to test uncancel");
+
+            var updatedSubscription = Chargify.UpdateDelayedCancelForSubscription(cancelledSubscription.SubscriptionID,
+                false, "Testing Undo Delayed Cancel");
+
+            Assert.IsFalse(updatedSubscription.CancelAtEndOfPeriod);
+        }
+
+        [TestMethod]
+        public void Chargify_exception_is_thrown_when_setting_delayed_cancel_of_invalid_subscription_to_true()
+        {
+            AssertTheFollowingThrowsException(() =>
+            {
+                Chargify.UpdateDelayedCancelForSubscription(GetRandomNegativeInt(), true,
+                    "No subscription exists by this number");
+            },
+                e =>
+                {
+                    var exception = (ChargifyException)e;
+                    Assert.AreEqual(exception.ErrorMessages.First(), "Subscription not found");
+                });
+        }
+
+        [TestMethod]
+        public void Chargify_exception_is_thrown_when_setting_delayed_cancel_of_invalid_subscription_to_false()
+        {
+            AssertTheFollowingThrowsException(() =>
+            {
+                Chargify.UpdateDelayedCancelForSubscription(GetRandomNegativeInt(), false,
+                    "No subscription exists by this number");
+            },
+                e =>
+                {
+                    var exception = (ChargifyException)e;
+                    Assert.AreEqual(exception.ErrorMessages.First(), "Subscription not found");
+                });
+        }
+
         [TestMethod, Ignore]
         public void Subscription_Update()
         {
diff --git a/Source/ChargifyDotNet/ChargifyConnect.cs b/Source/ChargifyDotNet/ChargifyConnect.cs
index 0e0f518..f734ef1 100644
--- a/Source/ChargifyDotNet/ChargifyConnect.cs
+++ b/Source/ChargifyDotNet/ChargifyConnect.cs
@@ -27,6 +27,9 @@
 //
 #endregion
 
+using System.Xml.Serialization;
+using Newtonsoft.Json;
+
 namespace ChargifyNET
 {
     #region Imports
@@ -241,7 +244,7 @@ public IMetafield GetMetafields<T>() where T : ChargifyBase
         /// <param name="chargifyId">The Chargify identifier for the resource</param>
         /// <param name="metadatum">The list of metadatum to set</param>
         /// <returns>The metadata result containing the response</returns>
-        public List<IMetadata> SetMetadataFor<T>(int chargifyId, List<Metadata> metadatum)
+        public List<IMetadata> SetMetadataFor<T>(long chargifyId, List<Metadata> metadatum)
         {
             // make sure data is valid
             if (metadatum == null) { throw new ArgumentNullException("metadatum"); }
@@ -318,7 +321,7 @@ public List<IMetadata> SetMetadataFor<T>(int chargifyId, List<Metadata> metadatu
         /// <param name="chargifyId">The Chargify identifier for the resource</param>
         /// <param name="metadata">The list of metadata to set</param>
         /// <returns>The metadata result containing the response</returns>
-        public List<IMetadata> SetMetadataFor<T>(int chargifyId, Metadata metadata)
+        public List<IMetadata> SetMetadataFor<T>(long chargifyId, Metadata metadata)
         {
             // make sure data is valid
             if (metadata == null) throw new ArgumentNullException(nameof(metadata));
@@ -394,7 +397,7 @@ public List<IMetadata> SetMetadataFor<T>(int chargifyId, Metadata metadata)
         /// <param name="resourceId">The Chargify identifier for the resource</param>
         /// <param name="page">Which page to return</param>
         /// <returns>The metadata result containing the response</returns>
-        public IMetadataResult GetMetadataFor<T>(int resourceId, int? page)
+        public IMetadataResult GetMetadataFor<T>(long resourceId, int? page)
         {
             string url;
             switch (typeof(T).Name.ToLowerInvariant())
@@ -454,7 +457,7 @@ public IMetadataResult GetMetadata<T>()
         /// </summary>
         /// <param name="chargifyId">The chargify ID of the customer</param>
         /// <returns>The customer with the specified chargify ID</returns>
-        public ICustomer LoadCustomer(int chargifyId)
+        public ICustomer LoadCustomer(long chargifyId)
         {
             try
             {
@@ -810,7 +813,7 @@ public IDictionary<string, ICustomer> SearchCustomers(string query)
         /// <param name="chargifyId">The integer identifier of the customer</param>
         /// <returns>True if the customer was deleted, false otherwise.</returns>
         /// <remarks>This method does not currently work, but it will once they open up the API. This will always return false, as Chargify will send a Http Forbidden everytime.</remarks>
-        public bool DeleteCustomer(int chargifyId)
+        public bool DeleteCustomer(long chargifyId)
         {
             try
             {
@@ -866,6 +869,7 @@ public bool DeleteCustomer(string systemId)
                 }
             }
         }
+        
 
         #endregion
 
@@ -1359,6 +1363,39 @@ public bool DeleteSubscription(int subscriptionId, string cancellationMessage)
             }
         }
 
+        /// <summary>
+        /// Purge the specified subscription
+        /// * This is undocumented behavior. It requires special permissions from chargify. Contact support to enable this feature. *
+        /// ** CAUTION:  Permanently deletes subscription and all transactions. There is no way to undo this! **
+        /// </summary>'
+        /// https://SUBDOMAIN_HERE.chargify.com/subscriptions/SUBSCRIPTION_ID_HERE/purge.json?ack=CUSTOMER_ID_HERE
+        /// <param name="subscriptionId">The id of the subscription</param>
+        /// <returns>True if the subscription was purged, false otherwise.</returns>
+        public bool PurgeSubscription(int subscriptionId) 
+        {
+            try
+            {
+                var subscription = LoadSubscription(subscriptionId);
+                if (subscription == null) { throw new ArgumentException("Not a valid subscription", "subscriptionId"); }
+
+                // now make the request
+                DoRequest(
+                    $"subscriptions/{subscriptionId}/purge.{GetMethodExtension()}?ack={subscription.Customer.ChargifyID}", HttpRequestMethod.Post, null);
+                return true;
+            }
+            catch (ChargifyException cex)
+            {
+                switch (cex.StatusCode)
+                {
+                    //case HttpStatusCode.Forbidden:
+                    //case HttpStatusCode.NotFound:
+                    //    return false;
+                    default:
+                        throw;
+                }
+            }
+        }
+
         /// <summary>
         /// Load the requested customer from chargify
         /// </summary>
@@ -1537,7 +1574,7 @@ private IDictionary<int, ISubscription> GetSubscriptionList(int page, int perPag
         /// </summary>
         /// <param name="chargifyId">The ChargifyID of the customer</param>
         /// <returns>A list of subscriptions</returns>
-        public IDictionary<int, ISubscription> GetSubscriptionListForCustomer(int chargifyId)
+        public IDictionary<int, ISubscription> GetSubscriptionListForCustomer(long chargifyId)
         {
             try
             {
@@ -1661,7 +1698,7 @@ public ISubscription CreateSubscription(ISubscriptionCreateOptions options)
         /// <param name="chargifyId">The Chargify ID of the customer</param>
         /// <param name="paymentCollectionMethod">Optional, type of payment collection method</param>
         /// <returns>The xml describing the new subsscription</returns>
-        public ISubscription CreateSubscription(string productHandle, int chargifyId, PaymentCollectionMethod? paymentCollectionMethod = PaymentCollectionMethod.Automatic)
+        public ISubscription CreateSubscription(string productHandle, long chargifyId, PaymentCollectionMethod? paymentCollectionMethod = PaymentCollectionMethod.Automatic)
         {
             // make sure data is valid
             if (chargifyId == int.MinValue) throw new ArgumentException("Invalid Customer ID detected", "chargifyId");
@@ -1676,7 +1713,7 @@ public ISubscription CreateSubscription(string productHandle, int chargifyId, Pa
         /// <param name="chargifyId">The Chargify ID of the customer</param>
         /// <param name="creditCardAttributes">The credit card attributes</param>
         /// <returns>The xml describing the new subsscription</returns>
-        public ISubscription CreateSubscription(string productHandle, int chargifyId, ICreditCardAttributes creditCardAttributes)
+        public ISubscription CreateSubscription(string productHandle, long chargifyId, ICreditCardAttributes creditCardAttributes)
         {
             // make sure data is valid
             if (creditCardAttributes == null) throw new ArgumentNullException("creditCardAttributes");
@@ -1696,7 +1733,7 @@ public ISubscription CreateSubscription(string productHandle, int chargifyId, IC
         /// <param name="creditCardAttributes">The credit card attributes to use for the new subscription</param>
         /// <param name="nextBillingAt">The date that should be used for the next_billing_at</param>
         /// <returns>The new subscription, if successful. Null otherwise.</returns>
-        public ISubscription CreateSubscription(string productHandle, int chargifyId, ICreditCardAttributes creditCardAttributes, DateTime nextBillingAt)
+        public ISubscription CreateSubscription(string productHandle, long chargifyId, ICreditCardAttributes creditCardAttributes, DateTime nextBillingAt)
         {
             // make sure data is valid
             if (creditCardAttributes == null) throw new ArgumentNullException("creditCardAttributes");
@@ -1712,7 +1749,7 @@ public ISubscription CreateSubscription(string productHandle, int chargifyId, IC
         /// <param name="chargifyId">The ID of the Customer to add the subscription for</param>
         /// <param name="couponCode">The discount coupon code</param>
         /// <returns>If sucessful, the subscription object. Otherwise null.</returns>
-        public ISubscription CreateSubscriptionUsingCoupon(string productHandle, int chargifyId, string couponCode)
+        public ISubscription CreateSubscriptionUsingCoupon(string productHandle, long chargifyId, string couponCode)
         {
             if (chargifyId == int.MinValue) throw new ArgumentException("Invalid Customer ID detected", "chargifyId");
             if (string.IsNullOrEmpty(couponCode)) throw new ArgumentException("CouponCode can't be empty", "couponCode");
@@ -1727,7 +1764,7 @@ public ISubscription CreateSubscriptionUsingCoupon(string productHandle, int cha
         /// <param name="creditCardAttributes">The credit card attributes to use for this transaction</param>
         /// <param name="couponCode">The discount coupon code</param>
         /// <returns></returns>
-        public ISubscription CreateSubscriptionUsingCoupon(string productHandle, int chargifyId, ICreditCardAttributes creditCardAttributes, string couponCode)
+        public ISubscription CreateSubscriptionUsingCoupon(string productHandle, long chargifyId, ICreditCardAttributes creditCardAttributes, string couponCode)
         {
             // make sure data is valid
             if (creditCardAttributes == null) throw new ArgumentNullException("creditCardAttributes");
@@ -2164,7 +2201,7 @@ public ISubscription CreateSubscriptionUsingCoupon(string productHandle, ICustom
         /// <param name="couponCode">The discount coupon code</param>
         /// <param name="paymentCollectionMethod">Optional, type of payment collection method</param>
         /// <returns>The xml describing the new subsscription</returns>
-        public ISubscription CreateSubscription(string productHandle, int chargifyId, string couponCode, PaymentCollectionMethod? paymentCollectionMethod)
+        public ISubscription CreateSubscription(string productHandle, long chargifyId, string couponCode, PaymentCollectionMethod? paymentCollectionMethod)
         {
             // make sure data is valid
             if (string.IsNullOrEmpty(productHandle)) throw new ArgumentNullException(nameof(productHandle));
@@ -2218,7 +2255,7 @@ public ISubscription CreateSubscription(string productHandle, int chargifyId, st
         /// <param name="firstName">The first name, as it appears on the credit card</param>
         /// <param name="lastName">The last name, as it appears on the credit card</param>
         /// <returns>The xml describing the new subsscription</returns>
-        private ISubscription CreateSubscription(string productHandle, int chargifyId, string fullNumber, int expirationMonth, int expirationYear,
+        private ISubscription CreateSubscription(string productHandle, long chargifyId, string fullNumber, int expirationMonth, int expirationYear,
                                                         string cvv, string billingAddress, string billingCity, string billingState, string billingZip,
                                                         string billingCountry, string couponCode, string firstName, string lastName)
         {
@@ -2281,7 +2318,7 @@ private ISubscription CreateSubscription(string productHandle, int chargifyId, s
         /// <param name="billingCountry">The billing country</param>
         /// <param name="couponCode">The discount coupon code</param>
         /// <returns>The xml describing the new subsscription</returns>
-        private ISubscription CreateSubscription(string productHandle, int chargifyId, string fullNumber, int expirationMonth, int expirationYear,
+        private ISubscription CreateSubscription(string productHandle, long chargifyId, string fullNumber, int expirationMonth, int expirationYear,
                                                         string cvv, string billingAddress, string billingCity, string billingState, string billingZip,
                                                         string billingCountry, string couponCode)
         {
@@ -3264,24 +3301,41 @@ public ISubscription UpdateDelayedCancelForSubscription(int subscriptionId, bool
         {
             if (subscriptionId == int.MinValue) throw new ArgumentNullException("subscriptionId");
 
-            // create XML for creation of customer
-            StringBuilder subscriptionXml = new StringBuilder(GetXmlStringIfApplicable());
-            subscriptionXml.Append("<subscription>");
-            subscriptionXml.AppendFormat("<cancel_at_end_of_period>{0}</cancel_at_end_of_period>", cancelAtEndOfPeriod ? "1" : "0");
-            if (!String.IsNullOrEmpty(cancellationMessage)) { subscriptionXml.AppendFormat("<cancellation_message>{0}</cancellation_message>", cancellationMessage); }
-            subscriptionXml.Append("</subscription>");
-            try
-            {
-                // now make the request
-                string response = DoRequest(string.Format("subscriptions/{0}.{1}", subscriptionId, GetMethodExtension()), HttpRequestMethod.Put, subscriptionXml.ToString());
-                // change the response to the object
-                return response.ConvertResponseTo<Subscription>("subscription");
-            }
-            catch (ChargifyException cex)
-            {
-                if (cex.StatusCode == HttpStatusCode.NotFound) throw new InvalidOperationException("Subscription not found");
-                throw;
-            }
+            bool isSuccessful = cancelAtEndOfPeriod
+                ? ApplyDelayedCancelToSubscription(subscriptionId, cancellationMessage)
+                : RemoveDelayedCancelFromSubscription(subscriptionId);
+          
+            if (isSuccessful)
+                return LoadSubscription(subscriptionId);
+            return null;
+
+        }
+
+        private bool ApplyDelayedCancelToSubscription(int subscriptionId, string cancellationMessage)
+        {
+            return HandleExceptions(attempt: () =>
+                {
+                    string response = DoRequest($"subscriptions/{subscriptionId}/delayed_cancel.{GetMethodExtension()}",
+                        HttpRequestMethod.Post, GetBody(new
+                        {
+                            subscription = new
+                            {
+                                cancellation_message = cancellationMessage
+                            }
+                        }));
+                    return true;
+                },
+                uponFailure: new ExceptionHandler().Add(@if: AttemptThrowsNotFoundStatusCode, then: HandleSubscriptionNotFound));
+        }
+
+        private bool RemoveDelayedCancelFromSubscription(int subscriptionId)
+        {
+            return HandleExceptions(attempt: () =>
+                {
+                    string response = DoRequest($"subscriptions/{subscriptionId}/delayed_cancel.{GetMethodExtension()}",HttpRequestMethod.Delete, null);
+                    return true;
+                },
+                uponFailure: new ExceptionHandler().Add(@if: AttemptThrowsNotFoundStatusCode, then: HandleSubscriptionNotFound));
         }
 
         /// <summary>
@@ -4180,7 +4234,7 @@ public IDictionary<int, IComponentAttributes> GetComponentsForSubscription(int s
         /// <param name="chargifyId">The product family ID</param>
         /// <param name="includeArchived">Filter flag for archived components</param>
         /// <returns>A dictionary of components if there are results, null otherwise.</returns>
-        public IDictionary<int, IComponentInfo> GetComponentsForProductFamily(int chargifyId, bool includeArchived)
+        public IDictionary<int, IComponentInfo> GetComponentsForProductFamily(long chargifyId, bool includeArchived)
         {
             // make sure data is valid
             if (chargifyId == int.MinValue) throw new ArgumentNullException("chargifyId");
@@ -4250,7 +4304,7 @@ public IDictionary<int, IComponentInfo> GetComponentsForProductFamily(int chargi
         /// </summary>
         /// <param name="chargifyId">The product family ID</param>
         /// <returns>A dictionary of components if there are results, null otherwise.</returns>
-        public IDictionary<int, IComponentInfo> GetComponentsForProductFamily(int chargifyId)
+        public IDictionary<int, IComponentInfo> GetComponentsForProductFamily(long chargifyId)
         {
             return GetComponentsForProductFamily(chargifyId, false);
         }
@@ -5366,7 +5420,7 @@ private IAdjustment CreateAdjustment(int subscriptionId, decimal amount, int amo
         /// <summary>
         /// From http://docs.chargify.com/api-billing-portal
         /// </summary>
-        public IBillingManagementInfo GetManagementLink(int chargifyId)
+        public IBillingManagementInfo GetManagementLink(long chargifyId)
         {
             try
             {
@@ -5385,6 +5439,95 @@ public IBillingManagementInfo GetManagementLink(int chargifyId)
                 throw;
             }
         }
+
+        /// <summary>
+        /// From http://docs.chargify.com/api-billing-portal
+        /// </summary>
+        /// <param name="chargifyId">The chargify ID of the customer</param>
+        /// <param name="autoInvite">Should an email be automatically sent to customer with billing portal link</param>
+        /// <returns>True if success, otherwise error is thrown</returns>
+        public bool EnableBillingPortalAccess(long chargifyId, bool autoInvite = false)
+        {
+            try
+            {
+                // make sure data is valid
+                if (chargifyId < 0) throw new ArgumentNullException("chargifyId");
+
+                // now make the request
+                string response = DoRequest(string.Format("portal/customers/{0}/enable.{1}?auto_invite={2}", chargifyId, GetMethodExtension(), autoInvite ? 1 : 0), HttpRequestMethod.Post, null);
+
+                return true;
+            }
+            catch (ChargifyException cex)
+            {
+                if (cex.StatusCode == HttpStatusCode.NotFound)
+                    throw new InvalidOperationException("Subscription not found");
+                throw;
+            }
+        }
+        /// <summary>
+        /// From http://docs.chargify.com/api-billing-portal
+        /// </summary>
+        /// <param name="systemId">The system ID of the customer</param>
+        /// <param name="autoInvite">Should an email be automatically sent to customer with billing portal link</param>
+        /// <returns>True if success, otherwise error is thrown</returns>
+
+        public bool EnableBillingPortalAccess(string systemId, bool autoInvite = false)
+        {
+            // make sure data is valid
+            if (systemId == string.Empty) throw new ArgumentException("Empty SystemID not allowed", "systemId");
+            var customer = LoadCustomer(systemId);
+            if (customer == null) throw new ArgumentException("Customer does not exist");
+
+            return EnableBillingPortalAccess(customer.ChargifyID, autoInvite);
+        }
+
+        /// <summary>
+        /// From http://docs.chargify.com/api-billing-portal
+        /// </summary>
+        /// <param name="chargifyId">The chargify ID of the customer</param>
+        /// <returns>True if success, otherwise error is thrown</returns>
+        public bool RevokeBillingPortalAccess(long chargifyId)
+        {
+            try
+            {
+                // make sure data is valid
+                if (chargifyId < 0) throw new ArgumentNullException("chargifyId");
+
+                // now make the request
+                string response = DoRequest(string.Format("portal/customers/{0}/invitations/revoke.{1}", chargifyId, GetMethodExtension()), HttpRequestMethod.Delete, null);
+
+                // Convert the Chargify response into the object we're looking for
+                return true;
+            }
+            catch (ChargifyException cex)
+            {
+                if (cex.StatusCode == HttpStatusCode.NotFound)
+                    throw new InvalidOperationException("Subscription not found");
+
+                if (cex.StatusCode == (HttpStatusCode)422)
+                {
+                    return true;
+                }
+                throw;
+            }
+        }
+
+        /// <summary>
+        /// From http://docs.chargify.com/api-billing-portal
+        /// </summary>
+        /// <param name="systemId">The system ID of the customer</param>
+        /// <returns>True if success, otherwise error is thrown</returns>
+
+        public bool RevokeBillingPortalAccess(string systemId)
+        {
+            // make sure data is valid
+            if (systemId == string.Empty) throw new ArgumentException("Empty SystemID not allowed", "systemId");
+            var customer = LoadCustomer(systemId);
+            if (customer == null) throw new ArgumentException("Customer does not exist");
+
+            return RevokeBillingPortalAccess(customer.ChargifyID);
+        }
         #endregion
 
         #region Invoices
@@ -5863,6 +6006,15 @@ public IReferralCode ValidateReferralCode(string ReferralCode)
         #endregion
 
         #region Utility Methods
+        private string GetBody(object obj)
+        {
+            var json = JsonConvert.SerializeObject(obj);
+            if (UseJSON)
+                return json;
+
+            var xmlNode = JsonConvert.DeserializeXmlNode(json);
+            return xmlNode.InnerXml;
+        }
         private Dictionary<int, T> GetListedJsonResponse<T>(string key, string response)
             where T : class, IChargifyEntity
         {
@@ -6287,5 +6439,30 @@ private string DoRequest(string methodString, HttpRequestMethod requestMethod, s
             }
         }
         #endregion
+
+        #region Exception Handling
+
+        private bool AttemptThrowsNotFoundStatusCode(ChargifyException e)
+        {
+            return e.StatusCode == HttpStatusCode.NotFound;
+        }
+        private void HandleSubscriptionNotFound(ChargifyException e)
+        {
+            throw new InvalidOperationException("Subscription not found");
+        }
+        private T HandleExceptions<T>(Func<T> attempt,
+            ExceptionHandler uponFailure)
+        {
+            try
+            {
+                return attempt();
+            }
+            catch (ChargifyException e)
+            {
+                uponFailure.Evaluate(e);
+                throw;
+            }
+        }
+        #endregion
     }
 }
\ No newline at end of file
diff --git a/Source/ChargifyDotNet/Customer.cs b/Source/ChargifyDotNet/Customer.cs
index a5ee898..c463670 100644
--- a/Source/ChargifyDotNet/Customer.cs
+++ b/Source/ChargifyDotNet/Customer.cs
@@ -145,7 +145,7 @@ private void LoadFromJSON(JsonObject obj)
                         CCEmails = obj.GetJSONContentAsString(key);
                         break;
                     case IdKey:
-                        _chargifyId = obj.GetJSONContentAsInt(key);
+                        ChargifyID = obj.GetJSONContentAsLong(key);
                         break;
                     case CreatedAtKey:
                         _created = obj.GetJSONContentAsDateTime(key);
@@ -213,7 +213,7 @@ private void LoadFromNode(XmlNode customerNode)
                         CCEmails = dataNode.GetNodeContentAsString();
                         break;
                     case IdKey:
-                        _chargifyId = dataNode.GetNodeContentAsInt();
+                        ChargifyID = dataNode.GetNodeContentAsLong();
                         break;
                     case CreatedAtKey:
                         _created = dataNode.GetNodeContentAsDateTime();
@@ -256,14 +256,8 @@ private void LoadFromNode(XmlNode customerNode)
         /// <summary>
         /// Get the customer's chargify ID
         /// </summary>
-        public int ChargifyID
-        {
-            get
-            {
-                return _chargifyId;
-            }
-        }
-        private int _chargifyId = int.MinValue;
+        public long ChargifyID { get; private set; } = long.MinValue;
+
         /// <summary>
         /// Get the date and time the customer was created a Chargify
         /// </summary>
@@ -295,7 +289,7 @@ public bool IsSaved
         {
             get
             {
-                return !(ChargifyID == int.MinValue);
+                return !(ChargifyID == long.MinValue);
             }
         }
 
diff --git a/Source/ChargifyDotNet/CustomerAttributes.cs b/Source/ChargifyDotNet/CustomerAttributes.cs
index 2cc0337..018096f 100644
--- a/Source/ChargifyDotNet/CustomerAttributes.cs
+++ b/Source/ChargifyDotNet/CustomerAttributes.cs
@@ -11,7 +11,7 @@
 //  Permission is hereby granted, free of charge, to any person obtaining a
 //  copy of this software and associated documentation files (the "Software"),
 //  to deal in the Software without restriction, including without limitation
-//  the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//  the rights to use, copy, modify, merge, publish, distribute, sub license,
 //  and/or sell copies of the Software, and to permit persons to whom the
 //  Software is furnished to do so, subject to the following conditions:
 //
@@ -142,7 +142,7 @@ public CustomerAttributes(string customerAttributesXml)
         internal CustomerAttributes(XmlNode customerAttributesNode)
         {
             if (customerAttributesNode == null) throw new ArgumentNullException(nameof(customerAttributesNode));
-            if (customerAttributesNode.Name != "customer_attributes") throw new ArgumentException("Not a vaild customer attributes node", nameof(customerAttributesNode));
+            if (customerAttributesNode.Name != "customer_attributes") throw new ArgumentException("Not a valid customer attributes node", nameof(customerAttributesNode));
             if (customerAttributesNode.ChildNodes.Count == 0) throw new ArgumentException("XML not valid", nameof(customerAttributesNode));
             LoadFromNode(customerAttributesNode);
         }
@@ -154,7 +154,7 @@ internal CustomerAttributes(XmlNode customerAttributesNode)
         public CustomerAttributes(JsonObject customerAttributesObject)
         {
             if (customerAttributesObject == null) throw new ArgumentNullException(nameof(customerAttributesObject));
-            if (customerAttributesObject.Keys.Count <= 0) throw new ArgumentException("Not a vaild customer attributes object", nameof(customerAttributesObject));
+            if (customerAttributesObject.Keys.Count <= 0) throw new ArgumentException("Not a valid customer attributes object", nameof(customerAttributesObject));
         }
 
         /// <summary>
diff --git a/Source/ChargifyDotNet/ExceptionHandler.cs b/Source/ChargifyDotNet/ExceptionHandler.cs
new file mode 100644
index 0000000..5c8e7c9
--- /dev/null
+++ b/Source/ChargifyDotNet/ExceptionHandler.cs
@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+
+namespace ChargifyNET
+{
+    internal sealed class ExceptionHandler
+    {
+        IDictionary<Func<ChargifyException, bool>, Action<ChargifyException>> ActionsToPerformUponFailure = new Dictionary<Func<ChargifyException, bool>, Action<ChargifyException>>();
+
+        public ExceptionHandler Add(Func<ChargifyException, bool> @if,
+            Action<ChargifyException> then)
+        {
+            ActionsToPerformUponFailure.Add(@if, then);
+            return this;
+        }
+
+        public bool Evaluate(ChargifyException e)
+        {
+            foreach (var action in ActionsToPerformUponFailure)
+            {
+                if (action.Key(e))
+                {
+                    action.Value(e);
+                    return false;
+                }
+            }
+
+            return true;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Source/ChargifyDotNet/Interfaces/IChargifyConnect.cs b/Source/ChargifyDotNet/Interfaces/IChargifyConnect.cs
index d4cc09a..d7ca6ef 100644
--- a/Source/ChargifyDotNet/Interfaces/IChargifyConnect.cs
+++ b/Source/ChargifyDotNet/Interfaces/IChargifyConnect.cs
@@ -127,14 +127,14 @@ public interface IChargifyConnect
         /// </summary>
         /// <param name="ChargifyID">The product family ID</param>
         /// <returns>A dictionary of components if there are results, null otherwise.</returns>
-        IDictionary<int, IComponentInfo> GetComponentsForProductFamily(int ChargifyID);
+        IDictionary<int, IComponentInfo> GetComponentsForProductFamily(long chargifyId);
         /// <summary>
         /// Method for getting a list of components for a specific product family
         /// </summary>
         /// <param name="ChargifyID">The product family ID</param>
         /// <param name="includeArchived">Filter flag for archived components</param>
         /// <returns>A dictionary of components if there are results, null otherwise.</returns>
-        IDictionary<int, IComponentInfo> GetComponentsForProductFamily(int ChargifyID, bool includeArchived);
+        IDictionary<int, IComponentInfo> GetComponentsForProductFamily(long chargifyId, bool includeArchived);
         /// <summary>
         /// Returns all components "attached" to that subscription.
         /// </summary>
@@ -242,7 +242,7 @@ public interface IChargifyConnect
         /// </summary>
         /// <param name="ChargifyId">The ID of the customer (not reference)</param>
         /// <returns>The billing portal management link and additional information</returns>
-        IBillingManagementInfo GetManagementLink(int ChargifyId);
+        IBillingManagementInfo GetManagementLink(long chargifyId);
         #endregion
 
         #region Invoices
@@ -284,16 +284,16 @@ public interface IChargifyConnect
         /// <param name="resourceID">The Chargify identifier for the resource</param>
         /// <param name="page">Which page to return</param>
         /// <returns>The metadata result containing the response</returns>
-        IMetadataResult GetMetadataFor<T>(int resourceID, int? page);
+        IMetadataResult GetMetadataFor<T>(long resourceID, int? page);
 
         /// <summary>
         /// Allows you to set a group of metadata for a specific resource
         /// </summary>
         /// <typeparam name="T">The type of resource. Currently either Subscription or Customer</typeparam>
-        /// <param name="chargifyID">The Chargify identifier for the resource</param>
+        /// <param name="chargifyId">The Chargify identifier for the resource</param>
         /// <param name="metadata">The list of metadata to set</param>
         /// <returns>The metadata result containing the response</returns>
-        List<IMetadata> SetMetadataFor<T>(int chargifyID, List<Metadata> metadata);
+        List<IMetadata> SetMetadataFor<T>(long chargifyId, List<Metadata> metadata);
 
         /// <summary>
         /// Allows you to set a single metadata for a specific resource
@@ -302,7 +302,7 @@ public interface IChargifyConnect
         /// <param name="chargifyID">The Chargify identifier for the resource</param>
         /// <param name="metadata">The list of metadata to set</param>
         /// <returns>The metadata result containing the response</returns>
-        List<IMetadata> SetMetadataFor<T>(int chargifyID, Metadata metadata);
+        List<IMetadata> SetMetadataFor<T>(long chargifyId, Metadata metadata);
         #endregion
 
         #region Sites
@@ -636,7 +636,7 @@ public interface IChargifyConnect
         /// <param name="ChargifyID">The integer identifier of the customer</param>
         /// <returns>True if the customer was deleted, false otherwise.</returns>
         /// <remarks>This method does not currently work, but it will once they open up the API. This will always return false, as Chargify will send a Http Forbidden everytime.</remarks>
-        bool DeleteCustomer(int ChargifyID);
+        bool DeleteCustomer(long chargifyId);
         /// <summary>
         /// Delete the specified customer
         /// </summary>
@@ -675,7 +675,7 @@ public interface IChargifyConnect
         /// </summary>
         /// <param name="ChargifyID">The chargify id of the customer</param>
         /// <returns>The requested customer, null otherwise</returns>
-        ICustomer LoadCustomer(int ChargifyID);
+        ICustomer LoadCustomer(long ChargifyID);
         /// <summary>
         /// Load the requested customer from chargify
         /// </summary>
@@ -938,7 +938,7 @@ public interface IChargifyConnect
         /// <param name="ChargifyID">The Chargify ID of the customer</param>
         /// <param name="PaymentCollectionMethod">Optional, type of payment collection method</param>
         /// <returns>The xml describing the new subsscription</returns>
-        ISubscription CreateSubscription(string ProductHandle, int ChargifyID, PaymentCollectionMethod? PaymentCollectionMethod = PaymentCollectionMethod.Automatic);
+        ISubscription CreateSubscription(string ProductHandle, long chargifyId, PaymentCollectionMethod? PaymentCollectionMethod = PaymentCollectionMethod.Automatic);
         /// <summary>
         /// Create a new subscription 
         /// </summary>
@@ -946,7 +946,7 @@ public interface IChargifyConnect
         /// <param name="ChargifyID">The Chargify ID of the customer</param>
         /// <param name="CreditCardAttributes">The credit card attributes</param>
         /// <returns>The xml describing the new subsscription</returns>
-        ISubscription CreateSubscription(string ProductHandle, int ChargifyID, ICreditCardAttributes CreditCardAttributes);
+        ISubscription CreateSubscription(string ProductHandle, long chargifyId, ICreditCardAttributes CreditCardAttributes);
         /// <summary>
         /// Create a subscription
         /// </summary>
@@ -955,8 +955,8 @@ public interface IChargifyConnect
         /// <param name="CreditCardAttributes">The credit card attributes to use for the new subscription</param>
         /// <param name="NextBillingAt">The date that should be used for the next_billing_at</param>
         /// <returns>The new subscription, if successful. Null otherwise.</returns>
-        ISubscription CreateSubscription(string ProductHandle, int ChargifyID, ICreditCardAttributes CreditCardAttributes, DateTime NextBillingAt);
-        //ISubscription CreateSubscription(string ProductHandle, int ChargifyID, ICreditCardAttributes CreditCardAttributes, DateTime NextBillingAt);
+        ISubscription CreateSubscription(string ProductHandle, long chargifyId, ICreditCardAttributes CreditCardAttributes, DateTime NextBillingAt);
+        //ISubscription CreateSubscription(string ProductHandle, long chargifyId, ICreditCardAttributes CreditCardAttributes, DateTime NextBillingAt);
         /// <summary>
         /// Create a subscription using a coupon for discounted rate, without using credit card information.
         /// </summary>
@@ -965,7 +965,7 @@ public interface IChargifyConnect
         /// <param name="CouponCode">The discount coupon code</param>
         /// <param name="paymentCollectionMethod">Optional, type of payment collection method</param>
         /// <returns>If sucessful, the subscription object. Otherwise null.</returns>
-        ISubscription CreateSubscription(string ProductHandle, int ChargifyID, string CouponCode, PaymentCollectionMethod? paymentCollectionMethod);
+        ISubscription CreateSubscription(string ProductHandle, long chargifyId, string CouponCode, PaymentCollectionMethod? paymentCollectionMethod);
         /// <summary>
         /// Create a new subscription without requiring credit card information
         /// </summary>
@@ -1066,7 +1066,7 @@ public interface IChargifyConnect
         /// <param name="CreditCardAttributes">The credit card attributes to use for this transaction</param>
         /// <param name="CouponCode">The discount coupon code</param>
         /// <returns></returns>
-        ISubscription CreateSubscriptionUsingCoupon(string ProductHandle, int ChargifyID, ICreditCardAttributes CreditCardAttributes, string CouponCode);
+        ISubscription CreateSubscriptionUsingCoupon(string ProductHandle, long chargifyId, ICreditCardAttributes CreditCardAttributes, string CouponCode);
         /// <summary>
         /// Create a new subscription 
         /// </summary>
@@ -1074,7 +1074,7 @@ public interface IChargifyConnect
         /// <param name="ChargifyID">The Chargify ID of the customer</param>
         /// <param name="CouponCode">The discount coupon code</param>
         /// <returns>The xml describing the new subsscription</returns>
-        ISubscription CreateSubscriptionUsingCoupon(string ProductHandle, int ChargifyID, string CouponCode);
+        ISubscription CreateSubscriptionUsingCoupon(string ProductHandle, long chargifyId, string CouponCode);
         /// <summary>
         /// Create a new subscription 
         /// </summary>
@@ -1163,7 +1163,7 @@ public interface IChargifyConnect
         /// </summary>
         /// <param name="ChargifyID">The ChargifyID of the customer</param>
         /// <returns>A list of subscriptions</returns>
-        IDictionary<int, ISubscription> GetSubscriptionListForCustomer(int ChargifyID);
+        IDictionary<int, ISubscription> GetSubscriptionListForCustomer(long chargifyId);
         /// <summary>
         /// Method to get the secure URL for updating the payment details for a subscription.
         /// </summary>
diff --git a/Source/ChargifyDotNet/Interfaces/ICustomer.cs b/Source/ChargifyDotNet/Interfaces/ICustomer.cs
index f9a30ac..a6ceeaa 100644
--- a/Source/ChargifyDotNet/Interfaces/ICustomer.cs
+++ b/Source/ChargifyDotNet/Interfaces/ICustomer.cs
@@ -43,7 +43,7 @@ public interface ICustomer : ICustomerAttributes, IComparable<ICustomer>
         /// <summary>
         /// Get the customer's chargify ID
         /// </summary>
-        int ChargifyID { get; }
+        long ChargifyID { get; }
         /// <summary>
         /// Get the date and time the customer was created a Chargify
         /// </summary>
diff --git a/Source/ChargifyDotNet/Interfaces/ISubscriptionCreateOptions.cs b/Source/ChargifyDotNet/Interfaces/ISubscriptionCreateOptions.cs
index 4b98e11..6111f64 100644
--- a/Source/ChargifyDotNet/Interfaces/ISubscriptionCreateOptions.cs
+++ b/Source/ChargifyDotNet/Interfaces/ISubscriptionCreateOptions.cs
@@ -58,7 +58,7 @@ public interface ISubscriptionCreateOptions
         /// The ID of an existing customer within Chargify. Required, 
         /// unless a customer_reference or a set of customer_attributes is given.
         /// </summary>
-        int? CustomerID { get; set; }
+        long? CustomerID { get; set; }
 
         /// <summary>
         /// The reference value (provided by your app) of an existing customer 
@@ -347,7 +347,7 @@ public bool ShouldSerializeCouponCode()
         /// unless a customer_reference or a set of customer_attributes is given.
         /// </summary>
         [XmlElement("customer_id")]
-        public int? CustomerID { get; set; }
+        public long? CustomerID { get; set; }
         /// <summary>
         /// Ignore, used to determine if the field should be serialized
         /// </summary>
diff --git a/Source/ChargifyDotNet/Json/JsonNumber.cs b/Source/ChargifyDotNet/Json/JsonNumber.cs
index 3eded2c..e8c70fb 100644
--- a/Source/ChargifyDotNet/Json/JsonNumber.cs
+++ b/Source/ChargifyDotNet/Json/JsonNumber.cs
@@ -9,6 +9,14 @@ public sealed class JsonNumber : JsonValue
     {
         double _value;
 
+        /// <summary>
+        /// The long value of this JsonNumber object (if applicable)
+        /// </summary>
+        public long LongValue
+        {
+            get { return (long)_value; }
+        }
+
         /// <summary>
         /// The Integer value of this JsonNumber object (if applicable)
         /// </summary>
diff --git a/Source/ChargifyDotNet/UsefulExtensions.cs b/Source/ChargifyDotNet/UsefulExtensions.cs
index db930a7..eaafbf2 100644
--- a/Source/ChargifyDotNet/UsefulExtensions.cs
+++ b/Source/ChargifyDotNet/UsefulExtensions.cs
@@ -670,6 +670,21 @@ public static string GetJSONContentAsString(this JsonObject obj, string key)
             return result;
         }
 
+        /// <summary>
+        /// Method for getting the content of an XmlNode as an long
+        /// </summary>
+        /// <param name="node">The node whose value needs to be extracted</param>
+        /// <returns>The long value of the node</returns>
+        public static long GetNodeContentAsLong(this XmlNode node)
+        {
+            long result = 0;
+            if (node.FirstChild != null)
+            {
+                if (!long.TryParse(node.FirstChild.Value, NumberStyles.Number, CultureInfo.InvariantCulture, out result)) result = 0;
+            }
+            return result;
+        }
+
         /// <summary>
         /// Method for getting the content of an XmlNode as an integer
         /// </summary>
@@ -708,6 +723,29 @@ public static int GetNodeContentAsInt(this XmlNode node)
             return result;
         }
 
+        /// <summary>
+        /// Method for getting the content of a JsonObject as an integer
+        /// </summary>
+        /// <param name="obj">The object whose value/key needs to be extracted</param>
+        /// <param name="key">The key of the int to retrieve</param>
+        /// <returns>The integer value of the keyed object</returns>
+        public static long GetJSONContentAsLong(this JsonObject obj, string key)
+        {
+            long result = 0;
+            if (obj != null)
+            {
+                if (obj.ContainsKey(key))
+                {
+                    JsonNumber value = obj[key] as JsonNumber;
+                    if (value != null)
+                    {
+                        result = value.LongValue;
+                    }
+                }
+            }
+            return result;
+        }
+
         /// <summary>
         /// Method for getting the content of a JsonObject as an integer
         /// </summary>