diff --git a/README.md b/README.md
index 9a1196e..11ac560 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,15 @@ docker run --env-file .env -p 5000:5000 -v /tmp/Krankenkassenverzeichnis_DiGA.xm
         "message": "DigaCodeValidationResponseError(errorCode=REQUEST_OR_DATA_INVALID, errorText=Anfrage oder Datei ungültig)",
         "path": "/validate/77AAAAAAAAAAAGIS"
     }
+
+    Example error response for diga test code when DISABLE_TESTCODES=true
+    {
+        "timestamp": "2021-08-23T09:38:32.385+00:00",
+        "status": 403,
+        "error": "Forbidden",
+        "message": "Testcodes are not allowed",
+        "path": "/validate/77AAAAAAAAAAAAAX"
+    }
     ```
   
 * POST /bill
diff --git a/src/main/kotlin/dev/gtuk/diga/AppExceptionHandler.kt b/src/main/kotlin/dev/gtuk/diga/AppExceptionHandler.kt
index 9fdf5a6..9187b54 100644
--- a/src/main/kotlin/dev/gtuk/diga/AppExceptionHandler.kt
+++ b/src/main/kotlin/dev/gtuk/diga/AppExceptionHandler.kt
@@ -1,6 +1,7 @@
 package dev.gtuk.diga
 
 import dev.gtuk.diga.exceptions.BillingException
+import dev.gtuk.diga.exceptions.TestCodesDisabledException
 import dev.gtuk.diga.exceptions.ValidationException
 import javax.servlet.http.HttpServletResponse
 import org.springframework.http.HttpStatus
@@ -19,4 +20,9 @@ class AppExceptionHandler {
     fun handleBillingException(e: BillingException, response: HttpServletResponse) {
         response.sendError(HttpStatus.BAD_REQUEST.value())
     }
+
+    @ExceptionHandler(TestCodesDisabledException::class)
+    fun handleCodeValidationException(e: TestCodesDisabledException, response: HttpServletResponse) {
+        response.sendError(HttpStatus.FORBIDDEN.value())
+    }
 }
diff --git a/src/main/kotlin/dev/gtuk/diga/DigaService.kt b/src/main/kotlin/dev/gtuk/diga/DigaService.kt
index 6ab1168..8048233 100644
--- a/src/main/kotlin/dev/gtuk/diga/DigaService.kt
+++ b/src/main/kotlin/dev/gtuk/diga/DigaService.kt
@@ -12,6 +12,7 @@ import dev.gtuk.diga.dtos.BillingResponse
 import dev.gtuk.diga.dtos.ValidationResponse
 import dev.gtuk.diga.exceptions.BillingException
 import dev.gtuk.diga.exceptions.CodeValidationException
+import dev.gtuk.diga.exceptions.TestCodesDisabledException
 import dev.gtuk.diga.exceptions.ValidationException
 import java.io.FileInputStream
 import kotlin.jvm.Throws
@@ -64,18 +65,20 @@ class DigaService(private val appConfig: AppConfig) {
         this.apiClient = DigaApiClient(apiClientSettings, digaInformation)
     }
 
-    @Throws(ValidationException::class)
+    @Throws(ValidationException::class, TestCodesDisabledException::class)
     fun verify(code: String): ValidationResponse {
         val isTestCode = Utils.isTestCode(code)
 
         val response: DigaCodeValidationResponse = try {
             if (isTestCode && appConfig.disableTestcodes) {
-                throw CodeValidationException("Testcodes are not allowed")
+                throw TestCodesDisabledException("Testcodes are not allowed")
             } else if (isTestCode) {
                 this.apiClient.sendTestCodeValidationRequest(Utils.getDigaTestCode(code), appConfig.testInsurance)
             } else {
                 this.apiClient.validateDigaCode(code)
             }
+        } catch (e: TestCodesDisabledException) {
+            throw e
         } catch (e: Exception) {
             logger.error("Validation errors", e)
 
diff --git a/src/main/kotlin/dev/gtuk/diga/exceptions/TestCodesDisabledException.kt b/src/main/kotlin/dev/gtuk/diga/exceptions/TestCodesDisabledException.kt
new file mode 100644
index 0000000..0c970ff
--- /dev/null
+++ b/src/main/kotlin/dev/gtuk/diga/exceptions/TestCodesDisabledException.kt
@@ -0,0 +1,3 @@
+package dev.gtuk.diga.exceptions
+
+class TestCodesDisabledException(message: String) : Exception(message)