Shopify used to hold one barcode per variant. Since 8 September 2026 it holds up to 20, and each one can have a type, as Shopify's changelog explains. That is how the EU's product identifiers (PIDs) fit into a Shopify product.
From 1 November 2026, the EU requires them on the customs declaration for every item sent to an EU customer (B2C). Our guide to the EU product identifier rules covers what each one is. If they are on your products in Shopify, Zenstores reads them from there and fills in the customs fields when you book a shipment to the EU, so there is nothing to enter in Zenstores.
Here is where each identifier goes in Shopify:
| Identifier | Where it goes in Shopify | What to enter |
|---|---|---|
| M-PID | The variant's SKU field | Your SKU |
| NS-PID | A barcode entry with the type NS-PID | The manufacturer's own code, such as a model, part or style number |
| S-PID | A barcode entry with the type GTIN, EAN, UPC or ISBN | The barcode number, where the product has one |
The NS-PID sits in Shopify's barcode field, but it is not a barcode. It is the manufacturer's own code.
- Gather the identifiers for each product
Pull together your SKU, the manufacturer's own product code, and a GTIN, EAN, UPC or ISBN where the product has one. The manufacturer's code is usually on the product label or packaging, or in your supplier's catalogue or datasheet. A product with no GTIN, EAN, UPC or ISBN doesn't need one. If you make the product yourself, you can use the same value, such as your SKU, for both the SKU and the NS-PID.
- Check every variant has its own SKU
Zenstores uses the variant's SKU as the M-PID, so each variant needs its own in Shopify's SKU field. The EU asks for each identifier to point to exactly one variant. The SKU is separate from the barcode field.
- Add the manufacturer's code as an NS-PID
On the variant details page, add a barcode, enter the manufacturer's code and choose NS-PID as the type. Keep the barcode you already use first and add the NS-PID after it, because Shopify's sales channels and apps read the first barcode on a variant.
- Add the GTIN, EAN, UPC or ISBN with its type
Add another barcode, enter the number and choose its type. Shopify checks the number against that standard's format as you enter it, so a mistyped digit is caught straight away. If a variant has more than one, Zenstores uses a GTIN first, then an EAN, then a UPC, then an ISBN.
- Update the rest of your catalogue in bulk
Use Shopify's bulk editor to update barcodes across many variants at once, or import and export them with the Variant Barcodes column in your product CSV. Zenstores syncs the identifiers from Shopify automatically and shares them with the carrier when an EU order is booked.
Populate M-PID, NS-PID and S-PID customs fields for EU orders
From 1 November 2026, orders to the EU require product identifiers in customs. Zenstores imports SKUs as well as codes like MPN, GTIN, ISBN, EAN from your store and adds them to the right customs fields so orders aren't held at the border.
Frequently Asked Questions
Where does the SKU go?
In the variant's SKU field, not the barcode field. Zenstores uses it as the M-PID, so each variant needs its own.
Can a variant hold more than one barcode in Shopify?
Yes. Since 8 September 2026, a variant can hold up to 20 barcodes, each with its own type. That is what lets you add the NS-PID alongside a GTIN or EAN.
Which type do I use for the manufacturer's code?
NS-PID. It is the manufacturer's own code, such as a model number, part number or style number, so it isn't always a barcode. Shopify keeps it in the barcode field.
Which barcode does Zenstores use as the S-PID if a variant has more than one?
A GTIN first, then an EAN, then a UPC, then an ISBN.
Which barcode should go first on a variant?
Leave the barcode you already use first, and add the NS-PID after it. Shopify's sales channels and apps read the first barcode on a variant, so changing the order could change what they see.
Can I add identifiers in bulk?
Yes. Shopify's bulk editor updates barcodes across many variants at once, and the Variant Barcodes column in your product CSV imports and exports the full set. Once they are saved, Zenstores syncs them from Shopify automatically.
Do I need to add anything in Zenstores?
No, if the identifiers are on your products in Shopify. They sync into Zenstores automatically, and Zenstores fills in the customs fields when you book a shipment to the EU. You can also add them to your SKUs in the Product List in Zenstores.
What if a product has no GTIN, EAN, UPC or ISBN?
You don't need one. The EU only asks for a standardised identifier where one exists, so the product can still ship. The SKU and the manufacturer's code are still required. Our guide to the EU product ID rules covers all three identifiers.
What happens if the SKU or the NS-PID is missing?
An EU shipment missing either one may fail when you book it. To catch it earlier, add a Zenstores Automations rule that holds EU orders with missing product IDs, so your team can fix the product and release the order. Our order checks and holds automations show how holds work.
What about WooCommerce and Magento?
This guide covers Shopify. For WooCommerce and Magento, add the identifiers to your SKUs in the Product List in Zenstores, or get in touch and we'll set up a custom mapping.
