diff --git a/src/Jobs/MigrateGTIN.php b/src/Jobs/MigrateGTIN.php
index 5b76df0ff6..081632a023 100644
--- a/src/Jobs/MigrateGTIN.php
+++ b/src/Jobs/MigrateGTIN.php
@@ -93,6 +93,11 @@ protected function process_items( array $items ) {
 				continue;
 			}
 
+			if ( $product->get_global_unique_id() ) {
+				$this->debug( $this->error_gtin_already_set( $product ) );
+				continue;
+			}
+
 			$gtin = $this->get_gtin( $product );
 
 			if ( ! $gtin ) {
diff --git a/tests/Unit/Admin/Product/Attributes/Input/AttributeInputCollectionTest.php b/tests/Unit/Admin/Product/Attributes/Input/AttributeInputCollectionTest.php
index 2cf127adf7..224f115ee6 100644
--- a/tests/Unit/Admin/Product/Attributes/Input/AttributeInputCollectionTest.php
+++ b/tests/Unit/Admin/Product/Attributes/Input/AttributeInputCollectionTest.php
@@ -19,6 +19,8 @@
 use Automattic\WooCommerce\GoogleListingsAndAds\Admin\Product\Attributes\Input\SizeInput;
 use Automattic\WooCommerce\GoogleListingsAndAds\Admin\Product\Attributes\Input\SizeSystemInput;
 use Automattic\WooCommerce\GoogleListingsAndAds\Admin\Product\Attributes\Input\SizeTypeInput;
+use Automattic\WooCommerce\GoogleListingsAndAds\Jobs\MigrateGTIN;
+use Automattic\WooCommerce\GoogleListingsAndAds\Options\OptionsInterface;
 use Automattic\WooCommerce\GoogleListingsAndAds\Product\Attributes\Adult;
 use Automattic\WooCommerce\GoogleListingsAndAds\Product\Attributes\AgeGroup;
 use Automattic\WooCommerce\GoogleListingsAndAds\Product\Attributes\AvailabilityDate;
@@ -36,6 +38,7 @@
 use Automattic\WooCommerce\GoogleListingsAndAds\Product\Attributes\SizeSystem;
 use Automattic\WooCommerce\GoogleListingsAndAds\Product\Attributes\SizeType;
 use Automattic\WooCommerce\GoogleListingsAndAds\Tests\Framework\UnitTest;
+use PHPUnit\Framework\MockObject\MockObject;
 
 /**
  * Class AttributeInputCollectionTest
@@ -45,6 +48,17 @@
  * @package Automattic\WooCommerce\GoogleListingsAndAds\Tests\Unit\Admin\Product\Attributes
  */
 class AttributeInputCollectionTest extends UnitTest {
+
+	/** @var MockObject|OptionsInterface $options */
+	protected $options;
+	/**
+	 * Runs before each test is executed.
+	 */
+	public function setUp(): void {
+		parent::setUp();
+		$this->options = $this->createMock( OptionsInterface::class );
+	}
+
 	public function test_adult_input() {
 		$input = new AdultInput();
 		$input
@@ -353,6 +367,36 @@ public function test_gtin_input() {
 		);
 	}
 
+	public function test_gtin_input_not_hidden() {
+		$input = new GTINInput();
+		$input->set_options_object( $this->options );
+		$this->options
+			->expects( $this->any() )
+			->method( 'get' )
+			->with( OptionsInterface::INSTALL_VERSION )
+			->willReturn( '2.8.6' );
+		$input
+			->set_id( GTIN::get_id() )
+			->set_name( GTIN::get_id() );
+		$input->set_field_visibility();
+		$this->assertFalse( $input->is_hidden() );
+	}
+
+	public function test_gtin_input_hidden() {
+		$input = new GTINInput();
+		$input->set_options_object( $this->options );
+		$this->options
+			->expects( $this->any() )
+			->method( 'get' )
+			->with( OptionsInterface::INSTALL_VERSION )
+			->willReturn( '2.8.8' );
+		$input
+			->set_id( GTIN::get_id() )
+			->set_name( GTIN::get_id() );
+		$input->set_field_visibility();
+		$this->assertTrue( $input->is_hidden() );
+	}
+
 	public function test_is_bundle_input() {
 		$input = new IsBundleInput();
 		$input
diff --git a/tests/Unit/Jobs/MigrateGTINTest.php b/tests/Unit/Jobs/MigrateGTINTest.php
new file mode 100644
index 0000000000..d1104a05ba
--- /dev/null
+++ b/tests/Unit/Jobs/MigrateGTINTest.php
@@ -0,0 +1,261 @@
+<?php
+declare( strict_types=1 );
+
+namespace Automattic\WooCommerce\GoogleListingsAndAds\Tests\Unit\Jobs;
+
+use Automattic\WooCommerce\GoogleListingsAndAds\ActionScheduler\ActionScheduler;
+use Automattic\WooCommerce\GoogleListingsAndAds\Jobs\ActionSchedulerJobMonitor;
+use Automattic\WooCommerce\GoogleListingsAndAds\Jobs\MigrateGTIN;
+use Automattic\WooCommerce\GoogleListingsAndAds\Options\OptionsInterface;
+use Automattic\WooCommerce\GoogleListingsAndAds\Product\Attributes\AttributeManager;
+use Automattic\WooCommerce\GoogleListingsAndAds\Product\ProductRepository;
+use Automattic\WooCommerce\GoogleListingsAndAds\Tests\Framework\UnitTest;
+use Automattic\WooCommerce\GoogleListingsAndAds\Tests\Tools\HelperTrait\ProductTrait;
+use PHPUnit\Framework\MockObject\MockObject;
+use WC_Helper_Product;
+
+/**
+ * Class MigrateGTINTest
+ *
+ * @see MigrateGTIN
+ * @package Automattic\WooCommerce\GoogleListingsAndAds\Tests\Unit\Jobs
+ */
+class MigrateGTINTest extends UnitTest {
+	use ProductTrait;
+
+	/** @var MockObject|ActionScheduler $action_scheduler */
+	protected $action_scheduler;
+
+	/** @var MockObject|ActionSchedulerJobMonitor $monitor */
+	protected $monitor;
+
+	/** @var MockObject|AttributeManager $attribute_manager */
+	protected $attribute_manager;
+
+	/** @var MockObject|ProductRepository $product_repository */
+	protected $product_repository;
+
+	/** @var MockObject|OptionsInterface $options */
+	protected $options;
+
+	/** @var MigrateGTIN $job */
+	protected $job;
+
+	protected const JOB_NAME          = 'migrate_gtin';
+	protected const CREATE_BATCH_HOOK = 'gla/jobs/' . self::JOB_NAME . '/create_batch';
+	protected const PROCESS_ITEM_HOOK = 'gla/jobs/' . self::JOB_NAME . '/process_item';
+
+	/**
+	 * Runs before each test is executed.
+	 */
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->action_scheduler   = $this->createMock( ActionScheduler::class );
+		$this->options            = $this->createMock( OptionsInterface::class );
+		$this->monitor            = $this->createMock( ActionSchedulerJobMonitor::class );
+		$this->product_repository = $this->createMock( ProductRepository::class );
+		$this->attribute_manager  = $this->createMock( AttributeManager::class );
+		$this->job                = new MigrateGTIN(
+			$this->action_scheduler,
+			$this->monitor,
+			$this->product_repository,
+			$this->attribute_manager
+		);
+
+		// reduce batch size for testing
+		add_filter(
+			'woocommerce_gla_batched_job_size',
+			function ( $batch_count, $job_name ) {
+				if ( self::JOB_NAME === $job_name ) {
+					return 3;
+				}
+				return $batch_count;
+			},
+			10,
+			2
+		);
+
+		$this->job->set_options_object( $this->options );
+		$this->job->init();
+	}
+
+	public function test_job_name() {
+		$this->assertEquals( self::JOB_NAME, $this->job->get_name() );
+	}
+
+	public function test_schedule_updates_status_to_started() {
+		$this->options->expects( $this->exactly( 1 ) )
+			->method( 'update' )
+			->with( OptionsInterface::GTIN_MIGRATION_STATUS, MigrateGTIN::GTIN_MIGRATION_STARTED );
+		$this->job->schedule();
+	}
+
+	public function test_completed_job_updates_status_to_completed() {
+		$this->options->expects( $this->exactly( 1 ) )
+			->method( 'update' )
+			->with( OptionsInterface::GTIN_MIGRATION_STATUS, MigrateGTIN::GTIN_MIGRATION_COMPLETED );
+		$this->job->handle_complete( 2 );
+	}
+
+	public function test_single_empty_batch() {
+		$this->product_repository->expects( $this->once() )
+			->method( 'find_all_product_ids' )
+			->willReturn( [] );
+
+		$this->action_scheduler->expects( $this->once() )
+			->method( 'has_scheduled_action' )->willReturn( false );
+
+		$this->action_scheduler->expects( $this->once() )
+			->method( 'schedule_immediate' )
+			->with( self::CREATE_BATCH_HOOK, [ 1 ] );
+
+		$this->job->schedule();
+
+		do_action( self::CREATE_BATCH_HOOK, 1 );
+	}
+
+	public function test_single_batch() {
+		$batch = [ 1, 2, 3 ];
+
+		$this->product_repository->expects( $this->once() )
+			->method( 'find_all_product_ids' )
+			->willReturn( $batch );
+
+		$this->action_scheduler->expects( $this->exactly( 3 ) )
+			->method( 'has_scheduled_action' )->willReturn( false );
+
+		$this->action_scheduler->expects( $this->exactly( 3 ) )
+			->method( 'schedule_immediate' )
+			->withConsecutive(
+				[ self::CREATE_BATCH_HOOK, [ 1 ] ],
+				[ self::PROCESS_ITEM_HOOK, [ $batch ] ]
+			);
+
+		$this->job->schedule();
+
+		do_action( self::CREATE_BATCH_HOOK, 1 );
+	}
+
+	public function test_multiple_batches() {
+		$batch_one   = [ 1, 2, 3 ];
+		$batch_two   = [ 4, 5, 6 ];
+		$batch_three = [];
+
+		$this->action_scheduler->expects( $this->exactly( 5 ) )
+			->method( 'schedule_immediate' )
+			->withConsecutive(
+				[ self::CREATE_BATCH_HOOK, [ 1 ] ],
+				[ self::PROCESS_ITEM_HOOK, [ $batch_one ] ],
+				[ self::CREATE_BATCH_HOOK, [ 2 ] ],
+				[ self::PROCESS_ITEM_HOOK, [ $batch_two ] ],
+				[ self::CREATE_BATCH_HOOK, [ 3 ] ],
+			);
+
+		$this->product_repository->expects( $this->exactly( 3 ) )
+			->method( 'find_all_product_ids' )
+			->withConsecutive( [ 3, 0 ], [ 3, 3 ], [ 3, 6 ] )
+			->willReturnOnConsecutiveCalls( $batch_one, $batch_two, $batch_three );
+
+		$this->action_scheduler
+			->method( 'has_scheduled_action' )
+			->willReturn( false );
+
+		$this->job->schedule();
+
+		do_action( self::CREATE_BATCH_HOOK, 1 );
+		do_action( self::CREATE_BATCH_HOOK, 2 );
+		do_action( self::CREATE_BATCH_HOOK, 3 );
+	}
+
+	public function test_process_item_is_called_by_hook() {
+		$this->product_repository
+			->expects( $this->once() )
+			->method( 'find_by_ids' )
+			->with( [ 1 ] );
+
+		do_action( self::PROCESS_ITEM_HOOK, [ 1 ] );
+	}
+
+	public function test_process_items_sucessfully_updates_gtin() {
+		$product = WC_Helper_Product::create_simple_product();
+		$this->product_repository
+			->expects( $this->once() )
+			->method( 'find_by_ids' )
+			->with( [ 1 ] )
+			->willReturn( [ $product ] );
+
+		$this->attribute_manager
+			->expects( $this->once() )
+			->method( 'get_value' )
+			->with( $product, 'gtin' )
+			->willReturn( '1234-5678' );
+
+		$this->assertEquals( $product->get_global_unique_id(), null );
+		$this->job->handle_process_items_action( [ 1 ] );
+		$this->assertEquals( $product->get_global_unique_id(), '12345678' );
+	}
+
+	public function test_process_items_not_updates_gtin_if_not_found() {
+		/** @var \WC_Product $product */
+		$product = WC_Helper_Product::create_simple_product();
+
+		$this->product_repository
+			->expects( $this->once() )
+			->method( 'find_by_ids' )
+			->with( [ 1 ] )
+			->willReturn( [ $product ] );
+
+		$this->attribute_manager
+			->expects( $this->once() )
+			->method( 'get_value' )
+			->with( $product, 'gtin' )
+			->willReturn( null );
+
+		$this->assertEquals( $product->get_global_unique_id(), null );
+		$this->job->handle_process_items_action( [ 1 ] );
+		$this->assertEquals( $product->get_global_unique_id(), null );
+	}
+
+	public function test_process_items_not_updates_gtin_if_already_set() {
+		/** @var \WC_Product $product */
+		$product = WC_Helper_Product::create_simple_product();
+		$product->set_global_unique_id( '11112222' );
+		$product->save();
+
+		$this->product_repository
+			->expects( $this->once() )
+			->method( 'find_by_ids' )
+			->with( [ 1 ] )
+			->willReturn( [ $product ] );
+
+		$this->attribute_manager
+			->expects( $this->never() )
+			->method( 'get_value' );
+
+		$this->assertEquals( $product->get_global_unique_id(), '11112222' );
+		$this->job->handle_process_items_action( [ 1 ] );
+		$this->assertEquals( $product->get_global_unique_id(), '11112222' );
+	}
+
+	public function test_process_items_not_updates_gtin_if_not_a_number() {
+		/** @var \WC_Product $product */
+		$product = WC_Helper_Product::create_simple_product();
+
+		$this->product_repository
+			->expects( $this->once() )
+			->method( 'find_by_ids' )
+			->with( [ 1 ] )
+			->willReturn( [ $product ] );
+
+		$this->attribute_manager
+			->expects( $this->once() )
+			->method( 'get_value' )
+			->with( $product, 'gtin' )
+			->willReturn( 'not a number' );
+
+		$this->assertEquals( $product->get_global_unique_id(), null );
+		$this->job->handle_process_items_action( [ 1 ] );
+		$this->assertEquals( $product->get_global_unique_id(), null );
+	}
+}