GTIN for Google Shopping: when you need one and identifier_exists

You need a GTIN for Google Shopping when the product you sell already has one assigned by its manufacturer: Google calls the attribute "recommended" for those products and says that products without a GTIN don't need one. If you sell your own brand, private-label goods, handmade items or one-off pieces that never received a GTIN, you submit brand and MPN instead, or set identifier_exists to no when the product genuinely has no identifiers at all.

That short answer hides a lot of practical detail. Google rejects codes with restricted prefixes, flags GTINs that belong to a different product, wants a separate number for every colour and size, and warns you when it thinks you have switched off identifiers that do exist. Getting this right decides whether your products show up properly in Shopping results or sit in Merchant Center with a "limited performance" label.

This guide explains what Google requires and recommends as of October 2026, how to tell whether a product should carry a GTIN in your feed, when identifier_exists is the right answer, how to fix the most common Merchant Center warnings, and how to set up feeds from Shopify and WooCommerce. If you are new to the numbers themselves, start with our guide what an EAN code is and how it is built.

What does Google Merchant Center require for GTINs?

A GTIN (Global Trade Item Number) is the umbrella name for the product numbers behind retail barcodes: the 13-digit EAN used in Europe, the 12-digit UPC used in North America, the 8-digit short codes for small packs, the 14-digit codes for multipacks and cartons, and the ISBN for books. In your product feed the attribute is simply called gtin.

Google's own GTIN attribute specification sets the status of the attribute as "recommended" for products that have a GTIN assigned by the manufacturer. In the same breath it says that products without a GTIN don't need one. The documentation also mentions an exception: you must provide a GTIN for non-physical items such as digital downloads. The exact wording and scope of that exception is worth checking on the live help page before you build a feed for digital goods, because Google adjusts its specifications from time to time.

So for most physical products the rule is conditional, not absolute. The question is never "does Google demand a GTIN from every seller?" but "does this particular product already have a GTIN somewhere in the supply chain?" If it does, Google wants to see it. If it does not, Google does not want you to invent one.

Required, recommended and optional: how the three identifiers fit together

Google talks about "unique product identifiers" (UPIs). There are three of them, and they work as a set:

Attribute	What it is	When to submit it
gtin	The manufacturer-assigned trade item number (EAN, UPC, JAN, ISBN, ITF-14)	Whenever the product has one
brand	The brand name as shown on the product or packaging	For practically every product that has a brand, including your own shop brand
mpn	Manufacturer part number, the model or part code the maker uses	When there is no GTIN, or in addition to it
identifier_exists	A switch that tells Google the product has no GTIN, no MPN and no brand	Only when you are certain none of the three exist

The unique product identifiers page adds one rule that trips up a lot of shops: do not put your SKU (your own stock code) into the GTIN, brand or MPN fields. A SKU is an internal reference, not a product identifier that anyone else recognises. The same goes for marketplace references such as Amazon's ASIN or FNSKU. Our comparison of EAN, UPC, GTIN, ISBN and the other codes explains why these are different things.

Why a correct GTIN helps your Google Shopping performance

Google is explicit that identifiers affect how your products perform. Its specification says that if a product does have a GTIN assigned, including it in your product data can increase the product's performance. It also says that products with a missing or incorrect GTIN may have limited visibility.

The reason is matching. When thousands of shops sell the same branded kettle, Google needs a reliable way to know that your listing and someone else's listing describe the same physical item. The GTIN is that key. With it, Google can attach your offer to the right product information, group it with other offers in comparison views, and show it for searches that mention the specific model. Without it, Google has to guess from titles and images, and a guess is weaker than a number.

GS1 France, which licenses barcodes in France, cites conversion uplifts of "up to 20%" for listings with correct GTINs. Treat that as GS1's own claim rather than an independent measurement, but the direction matches what Google itself says: for products that have a GTIN, leaving it out costs you visibility.

What makes a GTIN valid in Google Merchant Center?

Google checks every GTIN you submit against a set of format rules before it even looks at whether the number belongs to your product. If the number fails these checks, the item gets an "invalid GTIN" type issue. The rules are straightforward once you know them.

Accepted lengths and formats

Google accepts GTINs of 8, 12, 13 or 14 digits. Each corresponds to a familiar barcode type:

Code type	Digits	Typical use	Google's note
UPC (GTIN-12)	12	North America	Convert 8-digit UPC-E codes to 12 digits
EAN (GTIN-13)	13	Europe and most of the world	The standard format for most European sellers
JAN (GTIN-13)	8 or 13	Japan	Accepted in both lengths
ISBN	13 (or 10)	Books	Use the ISBN-13; convert ISBN-10 to ISBN-13
ITF-14 (GTIN-14)	14	Multipacks	Accepted for multipacks

Submit only the digits. No spaces, no dashes, no letters. A UPC printed as "0 12345 67890 5" goes into the feed as 012345678905.

The check digit must be correct

The last digit of every GTIN is a check digit, calculated from the digits before it using GS1's weighting of 1 and 3. Google tells sellers to verify it with GS1's check digit calculator. If one digit was mistyped, or two digits were swapped, the check digit will almost always fail and Google will reject the code as invalid.

For example, the illustrative number 8712345678906 has a valid check digit: the first twelve digits, weighted alternately 1 and 3, add up to 114, and 6 is what you need to reach 120. Change any single digit and the sum no longer works. You can test numbers with GS1's manual check digit method or with our EAN check digit guide and free calculator.

Keep in mind what the check digit proves. It shows that the number is well-formed. It does not show that the number was ever issued to anyone, or that it belongs to your product. A typed-in number that happens to pass the check can still be someone else's product.

Restricted and coupon prefixes are rejected

Some number ranges are reserved by GS1 for uses that are not normal trade items, such as in-store codes for products sold by weight, company-internal numbering and coupons. Google rejects GTINs that start with these prefixes:

Prefix	Reserved for	Google's treatment
02, 04, 2	Restricted circulation: in-store codes, variable weight items, company-internal use	Rejected as "restricted"
05, 98, 99	Coupons	Rejected as "coupon"
981–984	Coupons in common currency areas and similar uses	Rejected

This matters in practice. If your shop sells cheese, meat or other goods priced by weight, the barcode on the label from your scale probably starts with 2. That code works at your till but it is not a GTIN Google will accept, so leave it out of the gtin field. The same applies to internal codes your warehouse system generates.

One GTIN per product, per variant

Google states that each colour or size variant needs its own GTIN. It also says you should not use one GTIN for several different products in the same country and language. If you sell a T-shirt in three colours and four sizes, that is twelve sellable items and, if they carry GTINs, twelve different numbers. Our article on variants, bundles and when you need a new EAN covers how to count them.

Never guess or invent a GTIN

Google is blunt here: only provide a GTIN if you're sure it's correct, and do not make up or create new GTINs. Generating a random 13-digit number with a valid check digit produces something that looks fine but is either unassigned or, worse, belongs to an unrelated product made by someone else. Google treats both as incorrect data.

Does your product need a GTIN? A decision guide by product type

The fastest way to decide is to ask one question per product: did a manufacturer assign a GTIN to this exact item? The table below works through the situations most online shops face.

Your situation	GTIN in the feed?	What to submit
You resell a branded product made by someone else (a Philips shaver, a LEGO set)	Yes	The manufacturer's GTIN from the packaging, plus brand and ideally MPN
You sell your own brand and have already assigned EANs to your products	Yes, if you use those numbers on the product and across channels	Your GTIN, your brand, and an MPN if you have one
You sell your own brand or private label without any barcodes	No	Brand + MPN; leave gtin empty
Handmade or custom-made goods with no brand and no part number	No	identifier_exists = no
Antiques and one-off vintage pieces	No	identifier_exists = no
Books published since ISBNs became standard	Yes	The ISBN-13
Books published before 1970 without an ISBN	No	identifier_exists = no
A multipack sold by the manufacturer	Yes	The multipack's own GTIN (an ITF-14 is accepted)
A bundle you assembled yourself	Use the main product's identifiers	GTIN of the main item in the bundle, plus the bundle attribute where relevant
Digital downloads and other non-physical items	Google says a GTIN must be provided	Check the live Google page for the current wording

Two rows deserve extra attention. First, branded products you resell: here the GTIN is not optional in spirit. The product has one, other shops submit it, and if you leave it out your offer is harder for Google to match. Copy it from the physical packaging or the supplier's data sheet, not from another shop's website.

Second, your own products without barcodes. Google is clear that if you're the only seller of a product, or the product is a shop brand, it generally won't have a GTIN. For those items, brand plus MPN is the correct and complete answer.

Private label and shop brands: brand plus MPN instead of a GTIN

Many small sellers assume that Google Shopping forces them to buy barcodes. For Google alone, it does not. If you design and sell your own products under your own name, and you have not put GTINs on them, Google's guidance is to submit the brand and an MPN.

What to use as the brand

Use the brand name the customer sees on the product, the label or the packaging. For a shop brand that is usually your shop or label name, for example "Brand X" on a pair of socks. Do not write "generic", "none" or "unbranded" as a brand when the product actually carries your name, and do not put your shop's name in the brand field for products made by another company.

What to use as the MPN

An MPN is the part or model number that the maker of the product uses. If you are the maker, you are the one who assigns it. Many shops use a structured model code such as BXS-WOOL-BLK-42. The rules of thumb are simple:

• Give each distinct variant its own MPN, just as you would give it its own GTIN.
• Keep the MPN stable. Don't change it when you reprint labels or move warehouses.
• Print it somewhere on the product, packaging or invoice if you can, so it is a real part number and not only a feed value.
• Don't reuse your SKU blindly if it contains internal information such as a supplier code or a bin location. Google specifically warns against putting SKUs into identifier fields.

In practice many small brands do use the same string as both SKU and model number. That is fine as long as it really works as a model number: one per product variant, stable, and meaningful outside your stock system.

Should a private-label seller buy GTINs anyway?

For Google Shopping on its own, you don't have to. There are still good reasons to assign GTINs to your own products: you want to scan stock in a warehouse, you plan to sell on marketplaces that require an EAN (bol.com, Kaufland, Cdiscount and many eBay categories), or you want one identifier that follows the product across every channel. If you go that way, the choice of where the numbers come from matters more for marketplaces than for Google. Our honest comparison of GS1 membership and buying from a reseller walks through the options and their costs.

Once you have assigned GTINs to your own products and printed them on the packaging, submit them in the feed alongside brand and MPN. From that point on the product does have a GTIN, so identifier_exists = no would no longer be accurate.

When should you set identifier_exists to no?

The identifier_exists attribute tells Google that a product has no unique product identifiers. Google says to set it to no (or false) only when the product truly has no GTIN, no MPN and no brand, and only if you are certain. Its examples are custom or handmade goods, antiques and books published before 1970.

Good uses of identifier_exists = no

• A potter who sells unique, hand-thrown bowls without a brand label or model numbers.
• A dealer in second-hand antiques, where each piece is one of a kind.
• A second-hand bookshop selling titles from before ISBNs were in use.
• Made-to-order items where every piece is configured by the customer and there is no fixed model.

Bad uses that cause warnings

• Setting identifier_exists = no across the whole feed to make "missing GTIN" warnings disappear.
• Using it for branded products you resell, because you couldn't be bothered to find the barcode.
• Using it for your own-brand products that have a brand name. Those have a brand, so the correct route is brand plus MPN, not "no identifiers".
• Leaving it switched on after you later add EANs to those products.

Google says that if it finds evidence that a unique product identifier exists for a product you flagged as having none, you will get a warning. This is how it catches shortcuts: if your "unbranded" kettle looks exactly like a branded kettle that dozens of other shops list with a GTIN, Google notices.

A quick decision path

1. Does the product (or its packaging) carry a GTIN assigned by the manufacturer, or one you assigned yourself and use on the product? If yes, submit gtin and brand. Stop here.
2. If not, does it carry a brand name? If yes, submit brand and an mpn. Leave identifier_exists unset or set to yes.
3. If there is no GTIN and no brand, is there a part or model number? If yes, submit the mpn.
4. If there is no GTIN, no brand and no MPN, set identifier_exists = no.

Reseller EAN codes and Google Shopping: what you should know

A common situation for small brands: you bought EAN codes from a reseller for bol.com or your own shop, and now you want to know whether to put them in your Google feed. Here is how it works, as honestly as we can describe it.

How Google treats GTINs you assigned to your own products

Google's rules are about accuracy. The GTIN must be valid in format, must not use restricted or coupon prefixes, must be unique per variant, and must belong to the product you list. Google's documentation does not describe a check of who holds the GS1 licence for a number, in the way Amazon compares your brand with GS1's records. We have not found Google documentation that confirms or rules out such a check, so we can't promise how Google will treat a particular number.

What we can say is what the official sources say about the wider system. In GS1's own registry, Verified by GS1, a number bought from a reseller shows the original licence holder of the prefix, or no product data at all. It does not show your company. If Google or any other platform compares your listing with GS1 data, it will not find your brand there. That could lead to "incorrect GTIN" or mismatch warnings, although Google does not publicly document how it uses GS1 data.

Where a reseller EAN fits and where it does not

Situation	Reseller EAN reasonable?	Better option
Own webshop with Google Shopping, unbranded or own-brand products, codes also used on other channels that accept a valid unique EAN	Often workable, with the caveats above	Brand + MPN without a GTIN is equally legitimate for Google
Products you only sell through Google Shopping and your own shop, nowhere else	Not needed	Brand + MPN, or identifier_exists = no for handmade and one-offs
Branded products you also want on Amazon or bol.com	Poor fit	GS1 codes registered to you, or Amazon's GTIN exemption / Brand Registry
Products heading for supermarkets, retail chains or Zalando	No	GS1 membership
Resold branded goods from another manufacturer	Never	The manufacturer's own GTIN from the packaging

The last row is non-negotiable. Putting your own EAN on someone else's branded product, or replacing a manufacturer's GTIN in your feed, gives Google wrong data and causes exactly the "incorrect GTIN" issue described below.

If you already work with numbers from GTINcodes.com, each one is a valid EAN-13 from our stock, issued once and registered to you in the GTINcodes register. That means the same number has not been sold to another shop, which removes one common cause of conflicts. Anyone can check who a code is registered to in our register. That register is separate from GS1's: it records that you bought the number from GTINcodes.com and when, and it is not a GS1 registration. If you need your company to appear in GS1's registry, for retail chains, Zalando or branded products on Amazon and bol.com, GS1 membership is the right choice.

Decide before you scale

Whatever you choose, choose early. Changing the GTIN on a product that already has reviews and history on marketplaces can be painful; on Amazon, sellers report having to delete and relist products and losing reviews in the process. Google is more forgiving, because you can update a feed value at any time, but your other channels may not be. Our article on EAN codes for Amazon, the GTIN exemption and Brand Registry covers that side in detail.

Common Merchant Center GTIN warnings and how to fix them

Merchant Center reports identifier problems in its product diagnostics. The exact labels change as Google updates the interface, but the underlying causes fall into a handful of groups. Here are the ones shops run into most, with the fix for each.

"Missing GTIN" or "Limited performance due to missing identifiers"

What it means: Google believes the product has a GTIN (usually because other sellers submit one for what looks like the same item), but your feed doesn't include it.

How to fix it:

1. Find the barcode on the physical product or its packaging. For resold goods, ask your supplier or wholesaler for their product data, which almost always includes EAN or UPC.
2. Add the number to the gtin field, digits only.
3. Check that brand matches the manufacturer's brand exactly.
4. If the product really is your own design and has no GTIN, make sure brand and MPN are filled in. A missing-identifier warning on an own-brand product often means the MPN is empty.

"Invalid GTIN"

What it means: The number fails the format rules: wrong length, a wrong check digit, letters or spaces, or a restricted or coupon prefix.

How to fix it:

1. Count the digits. Anything other than 8, 12, 13 or 14 fails.
2. Check for lost leading zeros. A UPC such as 012345678905 becomes 12345678905 (11 digits) when a spreadsheet treats it as a number. Store GTIN columns as text.
3. Check for scientific notation. Spreadsheets sometimes turn 13-digit numbers into something like 8.71235E+12, which silently destroys the last digits. Fix the source data, not just the export.
4. Recalculate the check digit. If it fails, look for a typo against the physical barcode rather than "correcting" the last digit to make it pass.
5. Check the prefix. A code starting with 2, 02 or 04 is an in-store or internal code and should not be in the feed.
6. Convert UPC-E (8-digit compressed UPC) to its 12-digit UPC-A form and ISBN-10 to ISBN-13, as Google asks.

"Incorrect GTIN" (valid format, wrong product)

What it means: Google says the GTIN is valid in format but belongs to a different product. Its help page on this issue repeats the basic rule: do not make up or create new GTINs.

Typical causes and fixes:

• Copied from the wrong variant. The black size M has been given the GTIN of the white size L. Match each variant to its own barcode.
• Copied from a different edition. A new version of the product with a new GTIN, while your feed still uses the old one, or the other way round. Check the packaging of the stock you actually ship.
• Brand mismatch. The GTIN belongs to Brand A, but your feed says Brand B, for example because you entered your shop name as brand. Correct the brand field.
• An invented or reused number. Someone generated a number with a valid check digit or reused an old code for a new product. Replace it with a genuinely assigned GTIN, or remove it and use brand plus MPN.
• A number that was used for something else before you got it. This is a known risk with codes from sources that sell the same number more than once or recycle numbers. Use a different, unused number for your product and, before you print packaging, search the number online and in Verified by GS1 to see whether it is already tied to another product.

"Unsupported" or "coupon" GTIN

What it means: The number starts with a prefix that Google rejects (02, 04, 2, 05, 98, 99 or 981–984).

How to fix it: Remove the code from the gtin field. If the product has a proper GTIN as well (a weighed product may still have a fixed-weight version with its own EAN), use that. Otherwise submit brand and MPN.

Warning after setting identifier_exists = no

What it means: Google found evidence that a GTIN, brand or MPN exists for a product you flagged as having none.

How to fix it: Remove the identifier_exists = no value for that product and supply the identifiers that do exist. If you are certain the product has none (it is a one-off antique that resembles a mass-produced item, for example), make the title, description and images show clearly what it is.

Duplicate GTINs across different products

What it means: Two or more items in your feed share a GTIN, for the same country and language, while they are different products. This happens most often with variants that were all given the parent product's barcode.

How to fix it: Give each variant its own number. If you genuinely have only one barcode for several variants, the product was never correctly coded. Either assign GTINs to each variant or submit the variants without GTINs, using brand and a distinct MPN per variant.

A troubleshooting table you can keep next to Merchant Center

Symptom	Most likely cause	First thing to check
Many products flagged at once after an export	Spreadsheet stripped leading zeros or used scientific notation	Open the raw feed file and count digits
Only certain variants flagged	GTIN copied from parent to all variants	Compare GTINs within one product group
Resold branded product flagged as incorrect	Wrong edition or wrong variant code	Barcode on the stock in your warehouse
Own-brand products flagged as missing identifiers	Brand or MPN empty	Feed mapping for brand and mpn
Fresh-food items rejected	Scale label codes starting with 2	Remove those codes from gtin
Warning on items set to identifier_exists = no	Google found matching identifiers elsewhere	Whether the product really has a brand or GTIN

GTINs for variants, bundles and multipacks in a Google feed

Variants, bundles and multipacks are where most feeds go wrong, because shop systems often store one barcode per product rather than one per sellable item. Google's rules are clear for each case.

Variants: one GTIN per colour, size and material

Every variant a customer can choose is a separate trade item. GS1 Netherlands uses a simple example: black and white socks in three sizes are six products and need six codes, and three-packs of those socks need six more. In a Google feed each of those twelve items is a separate product line, grouped with item_group_id, and each carries its own GTIN if it has one.

If you sell your own products without GTINs, the same logic applies to MPNs. Give each variant a distinct model number so Google can tell them apart.

Multipacks from the manufacturer

When the manufacturer sells a pack of six as a product in its own right, that pack has its own GTIN, which may be a 14-digit ITF-14 number. Google accepts ITF-14 for multipacks. Use the multipack's GTIN, not the GTIN of the single unit inside.

Multipacks and bundles you create yourself

Google's rule for a bundle you assembled, for example a camera with a bag and a memory card, is to submit the identifiers of the main product. In this example that is the camera's GTIN. If the manufacturer created the bundle and gave it its own GTIN, use the manufacturer's bundle GTIN instead.

Outside Google, GS1's view is that whoever creates a bundle assigns it a new GTIN, and a change in the bundle's contents needs a new GTIN too. That matters if you want to list the same bundle on marketplaces that ask for an EAN. For Google Shopping, follow Google's rule; for marketplaces, follow theirs. Our guide to EANs for variants, bundles and product changes goes through the GS1 rules in full.

A worked example

Take a candle seller with her own label, "Brand X", who sells three scents in two sizes, plus a gift set of all three small candles.

Item	Without own GTINs	With own GTINs assigned
Lavender, small	brand: Brand X; mpn: BX-LAV-S	gtin: own EAN 1; brand; mpn
Lavender, large	brand: Brand X; mpn: BX-LAV-L	gtin: own EAN 2; brand; mpn
Cedar, small and large	mpn: BX-CED-S / BX-CED-L	own EAN 3 and 4
Fig, small and large	mpn: BX-FIG-S / BX-FIG-L	own EAN 5 and 6
Gift set (3 small)	mpn: BX-SET-3S	own EAN 7 if she treats it as her own product

In the left column she needs no barcodes at all for Google. In the right column she needs seven numbers, and if she later adds a fourth scent to the gift set, GS1's rules say the changed set is a new item with a new number. Either route is valid for Google Shopping as long as she is consistent and never sets identifier_exists = no for products that carry her brand.

Feed tips for Shopify, WooCommerce and spreadsheet feeds

Most GTIN problems in Merchant Center start in the shop system. The numbers are right on the packaging but wrong by the time they reach Google. A few habits prevent most of them.

Shopify: the barcode field and the 2026 change to barcodes

In the Shopify admin each variant has a "Barcode (ISBN, UPC, GTIN, etc.)" field. Google sales channel apps and most feed tools read that field and send it to Google as the GTIN, so fill it per variant, not just on the first variant.

Developers and feed-app builders should know about a change in Shopify's API. In API version 2026-10, announced on 8 September 2026, Shopify replaced the single barcode field with a barcodes connection that holds up to 20 identifiers per variant, each typed as UPC, EAN, ISBN, GTIN or ASIN and validated against its standard (see the Shopify developer changelog). That is useful, because it lets you store an EAN and an ASIN side by side without misusing one field. It also means a custom feed script that still reads barcode may need updating, and it should send only the GTIN-type value (UPC, EAN, ISBN or GTIN) to Google, never the ASIN.

WooCommerce and other platforms

WooCommerce and most other shop systems store a GTIN either in a dedicated product field or in a field added by a feed plugin. Whichever you use, the job is the same: make sure every variation has its own value, and map that field to Google's gtin attribute in your feed plugin. Map your model number field to mpn and your brand field or attribute to brand. Leave your SKU out of all three.

General feed hygiene

• Store GTINs as text everywhere. In spreadsheets, CSV imports and databases. This protects leading zeros and stops scientific notation.
• Don't put a 13-digit EAN in a field labelled UPC in systems that validate by type. It is a common error and it causes rejections. If your tool has a UPC field only, check whether it accepts 13 digits.
• Keep one source of truth. Assign GTINs in one place (your product information system or shop admin) and let every channel read from there. Copying numbers by hand into separate marketplace files is how variants end up swapped.
• Validate before you upload. A quick script or spreadsheet formula that checks the length and check digit catches most mistakes. GS1's method is described on its check digit page.
• Use supplemental feeds for fixes. If your shop export is hard to change, a supplemental feed in Merchant Center can overwrite gtin, mpn, brand or identifier_exists for specific product IDs.
• Keep identifiers stable. Changing GTINs on live products resets the matching Google has done. Only change a GTIN when the old one was wrong or the product itself changed.

A simple feed example

Here is how three different products look in a tab-separated or spreadsheet feed, showing the three routes side by side:

id	title	brand	gtin	mpn	identifier_exists
K-1001	Resold branded kettle, 1.7 l, steel	(manufacturer's brand)	(EAN from the box)	(maker's model number)	(empty)
BX-LAV-S	Brand X lavender candle, small	Brand X	(empty, or own EAN if assigned)	BX-LAV-S	(empty)
ANT-0042	Hand-carved oak chair, 19th century	(empty)	(empty)	(empty)	no

The first row follows the manufacturer's data. The second is a legitimate own-brand route without a GTIN. The third is the textbook case for identifier_exists = no.

GTINs for Google Shopping beyond the feed: other channels to consider

Google Shopping is usually one channel among several. The identifier strategy that suits Google on its own may not suit the rest of your sales, so it is worth checking the bigger picture before you decide whether to assign GTINs to your own products.

Channel	GTIN needed?	Must it be registered to you with GS1?
Google Shopping	Recommended if the product has one; not for shop brands and private label	Not documented by Google
Own webshop	No	No
eBay	In many categories; "Does not apply" is allowed	No documented check
Kaufland	Yes	Not documented
bol.com	Yes	Yes for branded items; unbranded currently not enforced (as of October 2026)
Amazon	Yes in most categories, or GTIN exemption / Brand Registry	Effectively yes for branded listings
Zalando, supermarkets, retail chains	Yes	Yes

If Google and your own shop are your only channels, brand plus MPN is a complete solution and costs nothing. If you also sell unbranded or own-brand goods on channels that ask for a valid, unique EAN, assigning one set of numbers and using them everywhere, Google included, keeps your data consistent. If your plans include branded listings on Amazon or bol.com, retail chains or Zalando, GS1 membership is the better choice from the start, because those channels check GS1's registry and expect to find your company there.

When you do use EANs bought from a reseller, keep evidence of where they came from. Our article on proving EAN ownership and handling disputes explains what counts as useful evidence and what its limits are. If you decide to buy codes, the prices and options are listed in our shops; GTINcodes.com codes are a one-off purchase, but they are not GS1 codes and do not appear under your name in Verified by GS1.

Checklist: getting GTINs right in Google Merchant Center

Run through this list before you upload a new feed or when Merchant Center starts reporting identifier problems.

1. Sort your products into three groups: products with a manufacturer GTIN, own-brand products, and products with no identifiers at all.
2. For resold branded goods, take the GTIN from the packaging or supplier data, and submit it with the manufacturer's brand and model number.
3. For own-brand and private-label goods without barcodes, submit brand and a distinct, stable MPN per variant. Leave gtin empty.
4. For own-brand goods with GTINs you assigned, submit the GTIN, brand and MPN, and make sure the same number is printed on the product and used on every channel.
5. Use identifier_exists = no only for handmade, custom, antique and other items with no GTIN, no brand and no MPN.
6. Check the format: 8, 12, 13 or 14 digits, a valid check digit, no spaces or dashes, UPC-E and ISBN-10 converted.
7. Remove restricted and coupon codes: nothing starting with 02, 04, 2, 05, 98, 99 or 981–984 in the gtin field.
8. Give every variant its own identifier: one GTIN, or one MPN, per colour, size and material.
9. For bundles you created, use the main product's identifiers; for manufacturer multipacks, use the multipack's own GTIN.
10. Never invent, guess or reuse a GTIN, and never put a SKU, ASIN or FNSKU into identifier fields.
11. Store GTINs as text in every spreadsheet and export, and validate them before upload.
12. Re-check Google's live help pages for the GTIN and identifier_exists attributes before large feed changes; the rules in this guide reflect the documentation as of October 2026.
13. Think beyond Google: if branded Amazon or bol.com listings, retail chains or Zalando are in your plans, choose GS1 codes early rather than switching later.