diff --git a/api-tests/core/content-type-builder/collection-type.test.api.js b/api-tests/core/content-type-builder/collection-type.test.api.js
index 124df1a074..ac0087a9ac 100644
--- a/api-tests/core/content-type-builder/collection-type.test.api.js
+++ b/api-tests/core/content-type-builder/collection-type.test.api.js
@@ -7,6 +7,7 @@
 const { createStrapiInstance } = require('api-tests/strapi');
 const { createAuthRequest } = require('api-tests/request');
 const modelsUtils = require('api-tests/models');
+const { createTestBuilder } = require('api-tests/builder');
 
 let strapi;
 let rq;
@@ -17,8 +18,28 @@ const restart = async () => {
   rq = await createAuthRequest({ strapi });
 };
 
+const builder = createTestBuilder();
+
+const localTestData = {
+  models: {
+    dog: {
+      singularName: 'dog',
+      pluralName: 'dogs',
+      collectionName: 'dogs-collection',
+      displayName: 'Dog Display',
+      kind: 'collectionType',
+      attributes: {
+        name: {
+          type: 'string',
+        },
+      },
+    },
+  },
+};
+
 describe('Content Type Builder - Content types', () => {
   beforeAll(async () => {
+    await builder.addContentType(localTestData.models.dog).build();
     strapi = await createStrapiInstance();
     rq = await createAuthRequest({ strapi });
   });
@@ -129,6 +150,54 @@ describe('Content Type Builder - Content types', () => {
       expect(res.body).toMatchSnapshot();
     });
 
+    test.each([
+      ['singularName', 'singularName'],
+      ['singularName', 'pluralName'],
+      ['pluralName', 'singularName'],
+      ['pluralName', 'pluralName'],
+      ['pluralName', 'collectionName'],
+    ])(`Cannot use %p that exists as another type's %p`, async (sourceField, matchField) => {
+      const body = {
+        contentType: {
+          displayName: 'Dog2',
+          pluralName: 'safe-plural-name',
+          singularName: 'safe-singular-name',
+          collectionName: 'safe-collection-name',
+          attributes: {
+            name: {
+              type: 'string',
+            },
+          },
+        },
+      };
+
+      // set the conflicting name in the given field
+      body.contentType[sourceField] = localTestData.models.dog[matchField];
+
+      const res = await rq({
+        method: 'POST',
+        url: '/content-type-builder/content-types',
+        body,
+      });
+
+      expect(res.statusCode).toBe(400);
+      expect(res.body).toEqual({
+        error: {
+          details: {
+            errors: [
+              {
+                message: `contentType: name \`${body.contentType[sourceField]}\` is already being used by another content type.`,
+                name: 'ValidationError',
+                path: ['contentType', sourceField],
+              },
+            ],
+          },
+          message: `contentType: name \`${body.contentType[sourceField]}\` is already being used by another content type.`,
+          name: 'ValidationError',
+        },
+      });
+    });
+
     test('Cannot use same string for singularName and pluralName', async () => {
       const res = await rq({
         method: 'POST',
diff --git a/packages/core/content-type-builder/server/controllers/validation/content-type.js b/packages/core/content-type-builder/server/controllers/validation/content-type.js
index 1062f6fb2f..e879979e7e 100644
--- a/packages/core/content-type-builder/server/controllers/validation/content-type.js
+++ b/packages/core/content-type-builder/server/controllers/validation/content-type.js
@@ -138,7 +138,7 @@ const nameIsAvailable = (isEdition) => {
 
   return {
     name: 'nameAlreadyUsed',
-    message: 'Content Type name `${value}` is already being used.',
+    message: 'contentType: name `${value}` is already being used by another content type.',
     test(value) {
       // don't check on edition
       if (isEdition) return true;
@@ -158,7 +158,7 @@ const nameIsNotExistingCollectionName = (isEdition) => {
 
   return {
     name: 'nameAlreadyUsed',
-    message: 'Content Type name `${value}` is already being used by another content type.',
+    message: 'contentType: name `${value}` is already being used by another content type.',
     test(value) {
       // don't check on edition
       if (isEdition) return true;
diff --git a/packages/core/content-type-builder/server/services/schema-builder/content-type-builder.js b/packages/core/content-type-builder/server/services/schema-builder/content-type-builder.js
index c65d162396..3aeea6345b 100644
--- a/packages/core/content-type-builder/server/services/schema-builder/content-type-builder.js
+++ b/packages/core/content-type-builder/server/services/schema-builder/content-type-builder.js
@@ -101,7 +101,7 @@ module.exports = function createComponentBuilder() {
       contentType
         .setUID(uid)
         .set('kind', infos.kind || typeKinds.COLLECTION_TYPE)
-        .set('collectionName', nameToCollectionName(infos.pluralName))
+        .set('collectionName', infos.collectionName || nameToCollectionName(infos.pluralName))
         .set('info', {
           singularName: infos.singularName,
           pluralName: infos.pluralName,