diff --git a/.github/workflows/generate-package.yml b/.github/workflows/generate-package.yml
index e0d702c..76f8d7a 100644
--- a/.github/workflows/generate-package.yml
+++ b/.github/workflows/generate-package.yml
@@ -34,6 +34,8 @@ jobs:
           mkdir $PLUGIN_NAME
           shopt -s extglob
           cp -r !($PLUGIN_NAME|.git*|.|..|tests) $PLUGIN_NAME
+          wget -O composer.phar https://getcomposer.org/composer-stable.phar
+          php composer.phar install -d ${PLUGIN_NAME}
           tar -zcvf $PLUGIN_NAME.tar.gz $PLUGIN_NAME
         shell: bash
       - name: Create the release
@@ -47,7 +49,7 @@ jobs:
           draft: false
           prerelease: false
       - name: Upload the package as release asset
-        id: upload-release-asset 
+        id: upload-release-asset
         uses: actions/upload-release-asset@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5657f6e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+vendor
\ No newline at end of file
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 633bf25..3807210 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -7,3 +7,7 @@ include:
     file:
       - 'templates/groups/pkp_plugin.yml'
       - 'templates/groups/omp/unit_tests.yml'
+
+.unit_test_template:
+  before_script:
+    - composer install
diff --git a/ThothPlugin.inc.php b/ThothPlugin.inc.php
index 47274c4..db1525d 100644
--- a/ThothPlugin.inc.php
+++ b/ThothPlugin.inc.php
@@ -36,7 +36,7 @@ public function register($category, $path, $mainContextId = null)
             $thothRegister = new ThothRegister($this);
             HookRegistry::register('Schema::get::submission', [$thothRegister, 'addWorkIdToSchema']);
             HookRegistry::register('Schema::get::eventLog', [$thothRegister, 'addReasonToSchema']);
-            HookRegistry::register('Form::config::before', [$thothRegister, 'addImprintField']);
+            HookRegistry::register('Form::config::before', [$thothRegister, 'addThothField']);
             HookRegistry::register('Publication::validatePublish', [$thothRegister, 'validateRegister']);
             HookRegistry::register('TemplateManager::display', [$thothRegister, 'addResources']);
             HookRegistry::register('Publication::publish', [$thothRegister, 'registerOnPublish']);
diff --git a/classes/ThothRegister.inc.php b/classes/ThothRegister.inc.php
index b0f1d0e..ad0a240 100644
--- a/classes/ThothRegister.inc.php
+++ b/classes/ThothRegister.inc.php
@@ -20,6 +20,7 @@
 use PKP\security\Role;
 
 import('plugins.generic.thoth.classes.facades.ThothService');
+import('plugins.generic.thoth.classes.ThothValidator');
 
 class ThothRegister
 {
@@ -52,7 +53,7 @@ public function addReasonToSchema($hookName, $args)
         return false;
     }
 
-    public function addImprintField($hookName, $form)
+    public function addThothField($hookName, $form)
     {
 
         if ($form->id !== 'publish' || !empty($form->errors)) {
@@ -65,48 +66,107 @@ public function addImprintField($hookName, $form)
             return;
         }
 
+        $errors = [];
+
         try {
             $thothClient = $this->plugin->getThothClient($submission->getData('contextId'));
             $publishers = $thothClient->linkedPublishers();
             $imprints = $thothClient->imprints(['publishers' => array_column($publishers, 'publisherId')]);
+        } catch (ThothException $e) {
+            $errors[] = __('plugins.generic.thoth.connectionError');
+            error_log($e->getMessage());
+        }
 
-            $imprintOptions = [];
-            foreach ($imprints as $imprint) {
-                $imprintOptions[] = [
-                    'value' => $imprint['imprintId'],
-                    'label' => $imprint['imprintName']
-                ];
-            }
+        if (empty($errors)) {
+            $errors = ThothValidator::validate($submission);
+        }
 
-            $form->addField(new \PKP\components\forms\FieldOptions('registerConfirmation', [
-                'label' => __('plugins.generic.thoth.register.label'),
-                'options' => [
-                    ['value' => true, 'label' => __('plugins.generic.thoth.register.confirmation')]
-                ],
-                'value' => false,
-                'groupId' => 'default',
-            ]))
-                ->addField(new \PKP\components\forms\FieldSelect('imprint', [
-                    'label' => __('plugins.generic.thoth.imprint'),
-                    'options' => $imprintOptions,
-                    'required' => true,
-                    'showWhen' => 'registerConfirmation',
-                    'groupId' => 'default',
-                    'value' => $imprints[0]['imprintId'] ?? null
-                ]));
-        } catch (ThothException $e) {
-            $warningIconHtml = '<span class="fa fa-exclamation-triangle pkpIcon--inline"></span>';
-            $noticeMsg = __('plugins.generic.thoth.connectionError');
-            $msg = '<div class="pkpNotification pkpNotification--warning">' . $warningIconHtml . $noticeMsg . '</div>';
+        if (!empty($errors)) {
+            $msg = '<div class="pkpNotification pkpNotification--warning">';
+            $msg .= __('plugins.generic.thoth.register.warning');
+            $msg .= '<ul>';
+            foreach ($errors as $error) {
+                $msg .= '<li>' . $error . '</li>';
+            }
+            $msg .= '</ul></div>';
 
             $form->addField(new \PKP\components\forms\FieldHTML('registerNotice', [
                 'description' => $msg,
                 'groupId' => 'default',
             ]));
 
-            error_log($e->getMessage());
+            return false;
+        }
+
+        $imprintOptions = [];
+        foreach ($imprints as $imprint) {
+            $imprintOptions[] = [
+                'value' => $imprint['imprintId'],
+                'label' => $imprint['imprintName']
+            ];
         }
 
+        $form->addField(new \PKP\components\forms\FieldOptions('registerConfirmation', [
+            'label' => __('plugins.generic.thoth.register.label'),
+            'options' => [
+                ['value' => true, 'label' => __('plugins.generic.thoth.register.confirmation')]
+            ],
+            'value' => false,
+            'groupId' => 'default',
+        ]))
+            ->addField(new \PKP\components\forms\FieldSelect('imprint', [
+                'label' => __('plugins.generic.thoth.imprint'),
+                'options' => $imprintOptions,
+                'required' => true,
+                'showWhen' => 'registerConfirmation',
+                'groupId' => 'default',
+                'value' => $imprints[0]['imprintId'] ?? null
+            ]));
+
+        // return false;
+
+        // try {
+        //     $thothClient = $this->plugin->getThothClient($submission->getData('contextId'));
+        //     $publishers = $thothClient->linkedPublishers();
+        //     $imprints = $thothClient->imprints(['publishers' => array_column($publishers, 'publisherId')]);
+
+        //     $imprintOptions = [];
+        //     foreach ($imprints as $imprint) {
+        //         $imprintOptions[] = [
+        //             'value' => $imprint['imprintId'],
+        //             'label' => $imprint['imprintName']
+        //         ];
+        //     }
+
+        //     $form->addField(new \PKP\components\forms\FieldOptions('registerConfirmation', [
+        //         'label' => __('plugins.generic.thoth.register.label'),
+        //         'options' => [
+        //             ['value' => true, 'label' => __('plugins.generic.thoth.register.confirmation')]
+        //         ],
+        //         'value' => false,
+        //         'groupId' => 'default',
+        //     ]))
+        //         ->addField(new \PKP\components\forms\FieldSelect('imprint', [
+        //             'label' => __('plugins.generic.thoth.imprint'),
+        //             'options' => $imprintOptions,
+        //             'required' => true,
+        //             'showWhen' => 'registerConfirmation',
+        //             'groupId' => 'default',
+        //             'value' => $imprints[0]['imprintId'] ?? null
+        //         ]));
+        // } catch (ThothException $e) {
+        //     $warningIconHtml = '<span class="fa fa-exclamation-triangle pkpIcon--inline"></span>';
+        //     $noticeMsg = __('plugins.generic.thoth.connectionError');
+        //     $msg = '<div class="pkpNotification pkpNotification--warning">' . $warningIconHtml . $noticeMsg . '</div>';
+
+        //     $form->addField(new \PKP\components\forms\FieldHTML('registerNotice', [
+        //         'description' => $msg,
+        //         'groupId' => 'default',
+        //     ]));
+
+        //     error_log($e->getMessage());
+        // }
+
         return false;
     }
 
diff --git a/classes/ThothValidator.inc.php b/classes/ThothValidator.inc.php
new file mode 100644
index 0000000..99950d4
--- /dev/null
+++ b/classes/ThothValidator.inc.php
@@ -0,0 +1,59 @@
+<?php
+
+/**
+ * @file plugins/generic/thoth/classes/ThothValidator.php
+ *
+ * Copyright (c) 2025 Lepidus Tecnologia
+ * Copyright (c) 2025 Thoth
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class ThothValidator
+ *
+ * @ingroup plugins_generic_thoth
+ *
+ * @brief Validate submission metadata to Thoth submit
+ */
+
+require_once(__DIR__ . '/../vendor/autoload.php');
+
+use Biblys\Isbn\Isbn;
+
+import('plugins.generic.thoth.classes.facades.ThothService');
+
+class ThothValidator
+{
+    public static function validate($submission)
+    {
+        $errors = [];
+
+        $publicationFormats = Application::getRepresentationDao()
+            ->getApprovedByPublicationId($submission->getData('currentPublicationId'))
+            ->toArray();
+
+        $publicationFormats = array_filter($publicationFormats, function ($publicationFormat) {
+            return $publicationFormat->getIsAvailable();
+        });
+
+        $errors = array_merge($errors, self::validateIsbn($publicationFormats));
+
+        return $errors;
+    }
+
+    public static function validateIsbn($publicationFormats)
+    {
+        $errors = [];
+        foreach ($publicationFormats as $publicationFormat) {
+            try {
+                $isbn = ThothService::publication()->getIsbnByPublicationFormat($publicationFormat);
+                Isbn::validateAsIsbn13($isbn);
+            } catch (Exception $e) {
+                $errors[] = __('plugins.generic.thoth.validation.isbn', [
+                    'isbn' => $isbn,
+                    'formatName' => $publicationFormat->getLocalizedName()
+                ]);
+            }
+        }
+
+        return $errors;
+    }
+}
diff --git a/classes/components/forms/RegisterForm.inc.php b/classes/components/forms/RegisterForm.inc.php
index ccd000b..8ee19a1 100644
--- a/classes/components/forms/RegisterForm.inc.php
+++ b/classes/components/forms/RegisterForm.inc.php
@@ -40,14 +40,18 @@ public function __construct($action, $imprints, $errors)
                 'pageId' => 'default',
             ]);
 
+            $msg = '<div class="pkpNotification pkpNotification--warning">';
+            $msg .= __('plugins.generic.thoth.register.warning');
+            $msg .= '<ul>';
             foreach ($errors as $error) {
-                $warningIconHtml = '<span class="fa fa-exclamation-triangle pkpIcon--inline"></span>';
-                $msg = '<div class="pkpNotification pkpNotification--warning">' . $warningIconHtml . $error . '</div>';
-                $this->addField(new \PKP\components\forms\FieldHTML('registerNotice', [
-                    'description' => $msg,
-                    'groupId' => 'default',
-                ]));
+                $msg .= '<li>' . $error . '</li>';
             }
+            $msg .= '</ul></div>';
+
+            $this->addField(new \PKP\components\forms\FieldHTML('registerNotice', [
+                'description' => $msg,
+                'groupId' => 'default',
+            ]));
 
             return;
         }
diff --git a/classes/services/ThothPublicationService.inc.php b/classes/services/ThothPublicationService.inc.php
index 22cd755..559b511 100644
--- a/classes/services/ThothPublicationService.inc.php
+++ b/classes/services/ThothPublicationService.inc.php
@@ -176,33 +176,10 @@ public function getIsbnByPublicationFormat($publicationFormat)
         $identificationCodes = $publicationFormat->getIdentificationCodes()->toArray();
         foreach ($identificationCodes as $identificationCode) {
             if ($identificationCode->getCode() == '15' || $identificationCode->getCode() == '24') {
-                $isbn = $identificationCode->getValue();
-                return $this->convertToIsbn13($isbn);
+                return $identificationCode->getValue();
             }
         }
 
         return null;
     }
-
-    public function convertToIsbn13($isbnString)
-    {
-        if (preg_match('/(?=.{17}$)97(?:8|9)([ -])\d{1,5}\1\d{1,7}\1\d{1,6}\1\d$/', $isbnString)) {
-            return $isbnString;
-        }
-
-        $isbnNumber = preg_replace('/\D/', '', $isbnString);
-
-        if (strlen($isbnNumber) != 13) {
-            return $isbnString;
-        }
-
-        return sprintf(
-            '%s-%s-%s-%s-%s',
-            substr($isbnNumber, 0, 3),
-            substr($isbnNumber, 3, 1),
-            substr($isbnNumber, 4, 2),
-            substr($isbnNumber, 6, 6),
-            substr($isbnNumber, 12, 1)
-        );
-    }
 }
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..84515fe
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,5 @@
+{
+    "require": {
+        "biblys/isbn": "~3.0"
+    }
+}
diff --git a/composer.lock b/composer.lock
new file mode 100644
index 0000000..2ac77c3
--- /dev/null
+++ b/composer.lock
@@ -0,0 +1,78 @@
+{
+    "_readme": [
+        "This file locks the dependencies of your project to a known state",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
+        "This file is @generated automatically"
+    ],
+    "content-hash": "30bd5da4e33de53f4f7c5b93d76d158f",
+    "packages": [
+        {
+            "name": "biblys/isbn",
+            "version": "3.2.9",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/biblys/isbn.git",
+                "reference": "88decabdccce7eed3f298f826e3365a00f895a05"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/biblys/isbn/zipball/88decabdccce7eed3f298f826e3365a00f895a05",
+                "reference": "88decabdccce7eed3f298f826e3365a00f895a05",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.2 || ^8.0"
+            },
+            "require-dev": {
+                "ext-json": "*",
+                "ext-simplexml": "*",
+                "guzzlehttp/guzzle": "^7.0",
+                "phpunit/phpunit": "^6 || ^7 || ^8 || ^11"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-0": {
+                    "Biblys": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Clement Latzarus",
+                    "email": "hello@clemlatz.dev"
+                }
+            ],
+            "description": "A PHP library to convert and validate ISBNs",
+            "homepage": "https://github.com/biblys/isbn",
+            "keywords": [
+                "ISBN",
+                "book",
+                "ean",
+                "gtin"
+            ],
+            "support": {
+                "issues": "https://github.com/biblys/isbn/issues",
+                "source": "https://github.com/biblys/isbn/tree/3.2.9"
+            },
+            "funding": [
+                {
+                    "url": "https://liberapay.com/clemlatz",
+                    "type": "liberapay"
+                }
+            ],
+            "time": "2022-11-26T00:00:00+00:00"
+        }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "stable",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": [],
+    "platform-dev": [],
+    "plugin-api-version": "2.6.0"
+}
diff --git a/controllers/modal/RegisterHandler.inc.php b/controllers/modal/RegisterHandler.inc.php
index 4488efb..b36a8bc 100644
--- a/controllers/modal/RegisterHandler.inc.php
+++ b/controllers/modal/RegisterHandler.inc.php
@@ -22,6 +22,7 @@
 use PKP\security\Role;
 
 import('classes.handler.Handler');
+import('plugins.generic.thoth.classes.ThothValidator');
 
 class RegisterHandler extends Handler
 {
@@ -90,6 +91,8 @@ public function register($args, $request)
             $thothClient = $plugin->getThothClient($submissionContext->getId());
             $publishers = $thothClient->linkedPublishers();
             $imprints = $thothClient->imprints(['publishers' => array_column($publishers, 'publisherId')]);
+
+            $errors = array_merge(ThothValidator::validate($this->submission), $errors);
         } catch (ThothException $e) {
             $errors[] = __('plugins.generic.thoth.connectionError');
             error_log($e->getMessage());
diff --git a/locale/en/locale.po b/locale/en/locale.po
index 33eeeb1..7897aeb 100644
--- a/locale/en/locale.po
+++ b/locale/en/locale.po
@@ -48,6 +48,12 @@ msgstr "Register"
 msgid "plugins.generic.thoth.register.label"
 msgstr "Thoth registration"
 
+msgid "plugins.generic.thoth.register.warning"
+msgstr "The submission metadata can not be submitted to Thoth because of the following errors:"
+
+msgid "plugins.generic.thoth.validation.isbn"
+msgstr "\"{$isbn}\" of \"{$formatName}\" publication format is not a valid ISBN-13. A valid ISBN-13 must be exactly 17 characters (numbers and hyphens)."
+
 msgid "plugins.generic.thoth.register.confirmation"
 msgstr "Do you want to register in Thoth the metadata related to this submission?"
 
diff --git a/locale/es/locale.po b/locale/es/locale.po
index 4a23595..1632c05 100644
--- a/locale/es/locale.po
+++ b/locale/es/locale.po
@@ -48,6 +48,12 @@ msgstr "Registrar"
 msgid "plugins.generic.thoth.register.label"
 msgstr "Registro en Thoth"
 
+msgid "plugins.generic.thoth.register.warning"
+msgstr "Los metadatos de envio no pueden ser enviados a Thoth debido a los siguientes errores:"
+
+msgid "plugins.generic.thoth.validation.isbn"
+msgstr "\"{$isbn}\" del formato de publicación \"{$formatName}\" no es un ISBN-13 válido. Un ISBN-13 válido debe tener exactamente 17 caracteres (números y guiones)."
+
 msgid "plugins.generic.thoth.register.confirmation"
 msgstr "¿Desea registrar en Thoth los metadatos relacionados con este envío?"
 
diff --git a/locale/pt_BR/locale.po b/locale/pt_BR/locale.po
index 293ec00..4db8476 100644
--- a/locale/pt_BR/locale.po
+++ b/locale/pt_BR/locale.po
@@ -48,6 +48,12 @@ msgstr "Registrar"
 msgid "plugins.generic.thoth.register.label"
 msgstr "Registro em Thoth"
 
+msgid "plugins.generic.thoth.register.warning"
+msgstr "Os metadados da submissão não podem ser enviados para Thoth devido aos seguintes erros:"
+
+msgid "plugins.generic.thoth.validation.isbn"
+msgstr "\"{$isbn}\" do formato de publicação \"{$formatName}\" não é um ISBN-13 válido. Um ISBN-13 válido deve ter exatamente 17 caracteres (números e hífens)."
+
 msgid "plugins.generic.thoth.register.confirmation"
 msgstr "Deseja realmente registrar na Thoth os metadados relacionados a essa submissão?"
 
diff --git a/tests/classes/ThothValidateTest.php b/tests/classes/ThothValidateTest.php
new file mode 100644
index 0000000..597b847
--- /dev/null
+++ b/tests/classes/ThothValidateTest.php
@@ -0,0 +1,89 @@
+<?php
+
+/**
+ * @file plugins/generic/thoth/tests/classes/ThothValidatorTest.php
+ *
+ * Copyright (c) 2025 Lepidus Tecnologia
+ * Copyright (c) 2025 Thoth
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class ThothValidatorTest
+ *
+ * @ingroup plugins_generic_thoth_tests
+ *
+ * @see ThothValidator
+ *
+ * @brief Test class for the ThothValidator class
+ */
+
+use PKP\tests\PKPTestCase;
+
+import('plugins.generic.thoth.classes.ThothValidator');
+
+class ThothValidatorTest extends PKPTestCase
+{
+    public function testISBNValidationFails()
+    {
+        $publicationFormats = [
+            Mockery::mock(\APP\publicationFormat\PublicationFormat::class)
+                ->makePartial()
+                ->shouldReceive('getLocalizedName')
+                ->withAnyArgs()
+                ->andReturn('PDF')
+                ->shouldReceive('getIdentificationCodes')
+                ->withAnyArgs()
+                ->andReturn(
+                    Mockery::mock(\PKP\db\DAOResultFactory::class)
+                        ->makePartial()
+                        ->shouldReceive('toArray')
+                        ->withAnyArgs()
+                        ->andReturn([
+                            Mockery::mock(\APP\publicationFormat\IdentificationCode::class)
+                                ->makePartial()
+                                ->shouldReceive('getCode')
+                                ->withAnyArgs()
+                                ->andReturn('24')
+                                ->shouldReceive('getValue')
+                                ->withAnyArgs()
+                                ->andReturn('97-83-9-579-61')
+                                ->getMock()
+                        ])
+                        ->getMock()
+                )
+                ->getMock(),
+            Mockery::mock(\APP\publicationFormat\PublicationFormat::class)
+                ->makePartial()
+                ->shouldReceive('getLocalizedName')
+                ->withAnyArgs()
+                ->andReturn('EPUB')
+                ->shouldReceive('getIdentificationCodes')
+                ->withAnyArgs()
+                ->andReturn(
+                    Mockery::mock(\PKP\db\DAOResultFactory::class)
+                        ->makePartial()
+                        ->shouldReceive('toArray')
+                        ->withAnyArgs()
+                        ->andReturn([
+                            Mockery::mock(\APP\publicationFormat\IdentificationCode::class)
+                                ->makePartial()
+                                ->shouldReceive('getCode')
+                                ->withAnyArgs()
+                                ->andReturn('15')
+                                ->shouldReceive('getValue')
+                                ->withAnyArgs()
+                                ->andReturn('978395796140')
+                                ->getMock()
+                        ])
+                        ->getMock()
+                )
+                ->getMock(),
+        ];
+
+        $errors = ThothValidator::validateIsbn($publicationFormats);
+
+        $this->assertEquals([
+            '##plugins.generic.thoth.validation.isbn##',
+            '##plugins.generic.thoth.validation.isbn##'
+        ], $errors);
+    }
+}
diff --git a/version.xml b/version.xml
index 4dc3d8e..4a4cacc 100644
--- a/version.xml
+++ b/version.xml
@@ -3,8 +3,8 @@
 <version>
 	<application>thoth</application>
 	<type>plugins.generic</type>
-	<release>0.2.1.5</release>
-	<date>2025-01-15</date>
+	<release>0.2.2.0</release>
+	<date>2025-01-18</date>
 	<lazy-load>1</lazy-load>
 	<class>ThothPlugin</class>
 </version>