diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/IdConflictTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/IdConflictTest.php
new file mode 100644
index 0000000000..a54cfd5ea6
--- /dev/null
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/IdConflictTest.php
@@ -0,0 +1,136 @@
+<?php
+
+namespace Drupal\Tests\migrate_drupal_ui\Functional\d6;
+
+use Drupal\Tests\migrate_drupal_ui\Functional\MigrateUpgradeExecuteTestBase;
+
+/**
+ * Tests Drupal 6 Id Conflict page.
+ *
+ * @group migrate_drupal_ui
+ */
+class IdConflictTest extends MigrateUpgradeExecuteTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'language',
+    'content_translation',
+    'config_translation',
+    'migrate_drupal_ui',
+    'telephone',
+    'aggregator',
+    'book',
+    'forum',
+    'statistics',
+    // Required for translation migrations.
+    'migrate_drupal_multilingual',
+  ];
+
+  /**
+   * The entity storage for node.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $nodeStorage;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->loadFixture(drupal_get_path('module', 'migrate_drupal') . '/tests/fixtures/drupal6.php');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getSourceBasePath() {
+    return __DIR__ . '/files';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEntityCounts() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEntityCountsIncremental() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getAvailablePaths() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getMissingPaths() {
+  }
+
+  /**
+   * Tests ID Conflict form.
+   */
+  public function testMigrateUpgradeExecute() {
+    $connection_options = $this->sourceDatabase->getConnectionOptions();
+    $this->drupalGet('/upgrade');
+    $session = $this->assertSession();
+    $session->responseContains('Upgrade a site by importing its files and the data from its database into a clean and empty new install of Drupal 8.');
+
+    $this->drupalPostForm(NULL, [], t('Continue'));
+    $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
+    $session->fieldExists('mysql[host]');
+
+    $driver = $connection_options['driver'];
+    $connection_options['prefix'] = $connection_options['prefix']['default'];
+
+    // Use the driver connection form to get the correct options out of the
+    // database settings. This supports all of the databases we test against.
+    $drivers = drupal_get_database_types();
+    $form = $drivers[$driver]->getFormOptions($connection_options);
+    $connection_options = array_intersect_key($connection_options, $form + $form['advanced_options']);
+    $version = $this->getLegacyDrupalVersion($this->sourceDatabase);
+    $edit = [
+      $driver => $connection_options,
+      'source_private_file_path' => $this->getSourceBasePath(),
+      'version' => $version,
+    ];
+    if ($version == 6) {
+      $edit['d6_source_base_path'] = $this->getSourceBasePath();
+    }
+    else {
+      $edit['source_base_path'] = $this->getSourceBasePath();
+    }
+    if (count($drivers) !== 1) {
+      $edit['driver'] = $driver;
+    }
+    $edits = $this->translatePostValues($edit);
+
+    // Start the upgrade process.
+    $this->drupalGet('/upgrade');
+    $session->responseContains('Upgrade a site by importing its files and the data from its database into a clean and empty new install of Drupal 8.');
+
+    $this->drupalPostForm(NULL, [], t('Continue'));
+    $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
+    $session->fieldExists('mysql[host]');
+
+    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $entity_types = [
+      'block_content',
+      'menu_link_content',
+      'file',
+      'taxonomy_term',
+      'user',
+      'comment',
+      'node',
+    ];
+    $this->assertIdConflict($session, $entity_types);
+  }
+
+}
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/IdConflictTest.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/IdConflictTest.php
new file mode 100644
index 0000000000..13081ee761
--- /dev/null
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/IdConflictTest.php
@@ -0,0 +1,138 @@
+<?php
+
+namespace Drupal\Tests\migrate_drupal_ui\Functional\d7;
+
+use Drupal\Tests\migrate_drupal_ui\Functional\MigrateUpgradeExecuteTestBase;
+
+/**
+ * Tests Drupal 7 Id Conflict page.
+ *
+ * @group migrate_drupal_ui
+ */
+class IdConflictTest extends MigrateUpgradeExecuteTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'file',
+    'language',
+    'config_translation',
+    'content_translation',
+    'migrate_drupal_ui',
+    'telephone',
+    'aggregator',
+    'book',
+    'forum',
+    'rdf',
+    'statistics',
+    // Required for translation migrations.
+    'migrate_drupal_multilingual',
+  ];
+
+  /**
+   * The entity storage for node.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $nodeStorage;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->loadFixture(drupal_get_path('module', 'migrate_drupal') . '/tests/fixtures/drupal6.php');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getSourceBasePath() {
+    return __DIR__ . '/files';
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEntityCounts() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getEntityCountsIncremental() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getAvailablePaths() {
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getMissingPaths() {
+  }
+
+  /**
+   * Tests ID Conflict form.
+   */
+  public function testMigrateUpgradeExecute() {
+    $connection_options = $this->sourceDatabase->getConnectionOptions();
+    $this->drupalGet('/upgrade');
+    $session = $this->assertSession();
+    $session->responseContains('Upgrade a site by importing its files and the data from its database into a clean and empty new install of Drupal 8.');
+
+    $this->drupalPostForm(NULL, [], t('Continue'));
+    $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
+    $session->fieldExists('mysql[host]');
+
+    $driver = $connection_options['driver'];
+    $connection_options['prefix'] = $connection_options['prefix']['default'];
+
+    // Use the driver connection form to get the correct options out of the
+    // database settings. This supports all of the databases we test against.
+    $drivers = drupal_get_database_types();
+    $form = $drivers[$driver]->getFormOptions($connection_options);
+    $connection_options = array_intersect_key($connection_options, $form + $form['advanced_options']);
+    $version = $this->getLegacyDrupalVersion($this->sourceDatabase);
+    $edit = [
+      $driver => $connection_options,
+      'source_private_file_path' => $this->getSourceBasePath(),
+      'version' => $version,
+    ];
+    if ($version == 6) {
+      $edit['d6_source_base_path'] = $this->getSourceBasePath();
+    }
+    else {
+      $edit['source_base_path'] = $this->getSourceBasePath();
+    }
+    if (count($drivers) !== 1) {
+      $edit['driver'] = $driver;
+    }
+    $edits = $this->translatePostValues($edit);
+
+    // Start the upgrade process.
+    $this->drupalGet('/upgrade');
+    $session->responseContains('Upgrade a site by importing its files and the data from its database into a clean and empty new install of Drupal 8.');
+
+    $this->drupalPostForm(NULL, [], t('Continue'));
+    $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
+    $session->fieldExists('mysql[host]');
+
+    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $entity_types = [
+      'block_content',
+      'menu_link_content',
+      'file',
+      'taxonomy_term',
+      'user',
+      'comment',
+      'node',
+    ];
+    $this->assertIdConflict($session, $entity_types);
+  }
+
+}