How to Add GTIN to Shopify, WooCommerce and BigCommerce

Your new EAN codes are sitting in a spreadsheet, and your shop has 60 products with 240 variants between them. Google Merchant Center is complaining about missing GTINs, and Amazon wants a product ID before you can list. The job now is to get the right number onto the right variant. Here's how to add GTIN to Shopify, WooCommerce and BigCommerce, how to do it in bulk, and how to make sure the numbers reach your product feeds.

The principle is the same on every platform: one GTIN per variant, entered in the platform's dedicated identifier field, never in the SKU or description.

Before you start: prepare a clean mapping

Doing the mapping in a spreadsheet first saves you hours of clicking. Make one row per variant, with these columns:

Then run the whole EAN column through our EAN checker. One wrong digit means a mismatch on the live product and an "invalid GTIN" warning later. GS1 UK's rule of thumb is a GTIN for each variety, so if your sheet has 240 variant rows, you need 240 numbers.

Cushion cover 'Harbour'

	Navy	Ochre	Linen
45 × 45 cm	…00013	…00020	…00037
60 × 60 cm	…00044	…00051	…00068

6 variants = 6 GTINs

How to add GTIN to Shopify

One product at a time

1. In Shopify admin, go to Products and open the product.
2. If the product has variants, click the variant (for example "Navy / 45 × 45 cm").
3. Find the Barcode field in the inventory section, next to SKU. Shopify describes it as the field for ISBN, UPC, GTIN and similar.
4. Paste the 13-digit EAN and save. Repeat for each variant.

For a product without variants, the Barcode field is on the product page itself.

In bulk

For more than a handful of products, use one of these:

• Bulk editor: select products in the Products list, choose bulk edit, and add the Barcode column. It's quick for up to a few hundred variants.
• CSV export and import: export your products, fill the variant barcode column for each variant row, and import with the option to overwrite existing products. Test with a small export first.

Getting it into Google

Shopify's Google channel reads the Barcode field and sends it as the GTIN. In Shopify Community threads, merchants have repeatedly reported that a product flagged as a custom product in the Google channel is sent as having no identifiers, even when the Barcode field is filled. If you see "missing GTIN" warnings for products that clearly have a barcode, check that flag first.

How to add GTIN in WooCommerce

Recent WooCommerce versions include a built-in field for GTIN, UPC, EAN or ISBN in the product's Inventory tab, so you no longer need a plugin just to store the number. For variable products, open Variations, expand each variation and fill the same field there.

On an older WooCommerce installation without that field, a plugin or your feed plugin usually adds its own GTIN field. Check which field your Google feed plugin actually reads before you fill anything, otherwise you'll enter the numbers in a place the feed ignores.

For bulk updates, WooCommerce's built-in CSV product exporter and importer handles variations as separate rows. Export, add the GTIN to each variation row, and re-import with "update existing products" switched on.

How to add GTIN in BigCommerce

BigCommerce keeps product identifiers in a dedicated section of the product editor, with separate fields for SKU, MPN and the barcode number (UPC/EAN and GTIN). For products with variants, each variant has its own identifier fields in the variant table. Bulk updates work through BigCommerce's product CSV export and import.

If you also sell on Amazon.co.uk or eBay.co.uk through a channel connector, check which field the connector maps to the marketplace's product ID. Connectors don't always use the same field as your Google feed.

Other platforms and custom shops

If your platform has no dedicated identifier field, you have two options: a custom field (often called a metafield or custom attribute) that your feed tool maps to gtin, or a feed tool that pulls the number from a separate spreadsheet. On your product pages, adding the GTIN to your product structured data helps search engines match your page to the right product.

1. SpreadsheetOne validated EAN per variant
2. Shop fieldBarcode / GTIN field per variant
3. Feed or channelMaps the field to gtin
4. Google, AmazonMatch the product by GTIN

Getting GTINs into your product feeds

Your shop field is only half the job. Google Merchant Center reads three related attributes:

• gtin: the 13-digit EAN. Google accepts numbers only, in 8, 12, 13 or 14 digits, with a correct check digit. It rejects GTINs starting with 02, 04 or 2 (restricted ranges) and coupon ranges 05, 98 and 99.
• brand: your brand name, sent alongside the GTIN.
• identifier_exists: set to no only when the product genuinely has no GTIN, MPN or brand, such as custom or handmade items. Google warns products set to no that show evidence of an identifier.

Google also states that you should only use GTINs as they have been assigned by the manufacturer, and never guess or make up a value. If you resell someone else's branded product, use the GTIN printed on their packaging. If you make the product and have given it its own EAN, that is the number on your packaging and the one to send. If your own-brand product has no EAN at all, don't invent one: Google's guidance for store brands is to submit brand and MPN instead.

Worked example: a 60-product homeware shop on Shopify

Imagine you sell 60 products with 240 variants. You:

1. Export the products to CSV and delete all columns except the handle, option values, SKU and variant barcode.
2. Paste your EANs in the barcode column, starting with 5060123456004 for "Harbour cushion cover / Navy / 45 × 45 cm".
3. Run the column through the EAN checker: 239 pass, 1 fails because a digit was transposed. You fix it.
4. Import 10 rows first, check them in admin, then import the remaining 230.
5. In the Google channel, make sure none of the 240 variants is flagged as a custom product.
6. Wait for the next feed sync, then check Merchant Center's Needs attention tab. Google says changes there can take 24 to 72 hours to appear.

Common import mistakes and how to avoid them

Most GTIN problems in online shops come from the import, not from the numbers themselves. These are the ones we see most often:

• Numbers turned into scientific notation. Excel and Google Sheets display a 13-digit number as 5.06012E+12 and may save it that way. Format the EAN column as text before you paste anything into it, and open CSV files through the import wizard rather than double-clicking them.
• The same EAN on two variants. A copy-and-drag in a spreadsheet can repeat a number down the column. Sort by EAN and look for duplicates before importing; every row must be unique.
• Numbers on the parent product only. On variable products, the parent row is a container. If the EAN sits there and not on the variant rows, feeds send nothing for the variants that customers actually buy.
• Overwriting live data. An import with "overwrite existing products" can wipe fields you left blank in the file. Export a full backup first, and keep it until the new numbers are confirmed in your feeds.
• Old numbers recycled. Giving a discontinued product's EAN to a new product causes mismatched listings and reviews. Read when you need a new EAN before you reassign anything.

A ten-minute check of the file before import saves hours of fixing warnings afterwards.

When our codes aren't the right fit

If you're selling your own brand on Amazon and want Brand Registry, supplying supermarkets or chains, or working with partners that check Verified by GS1, you need numbers licensed from GS1 UK. Our codes won't show your company in the GS1 registry, and Amazon's Seller Central text, as reproduced by GS1 Australia, says UPCs that don't match the information provided by GS1 will be considered invalid. For unbranded goods and webshops selling through their own site, Google Shopping and marketplaces without a GS1 check, our codes are a practical, one-off purchase.

What to do now

• Build a variant-level spreadsheet and validate every EAN with the EAN checker.
• Fill the identifier field per variant on your platform, using bulk import for larger ranges.
• Check that your feed or channel actually sends the field as gtin, with brand.
• Fix any "custom product" or identifier_exists flags on products that have a barcode.
• For Google warnings, follow our Merchant Center GTIN guide.