> ## Documentation Index
> Fetch the complete documentation index at: https://docs.global-e.com/llms.txt
> Use this file to discover all available pages before exploring further.
# EU Product Identifiers
Part of the [EU Customs Reform - Product Identifiers (PID)](/eu-product-identifiers-pid).
On Centra, `standardcode` is read automatically from the native Centra barcode field (GTIN for DTC, EAN for Checkout API) — no custom attribute needed for it. `mididentifier` is stored on each variant using the `ge_variant_data` custom attribute. Both are mapped at checkout. Your SKU is already sent separately, so there is no new SKU field to add. Do not use the US MID fields for EU PID.
For what each identifier is, see [The three identifiers](/eu-product-identifiers-pid#the-three-identifiers) on the overview page.
## What you need to do
1. **Create the Global-e attribute type.** In Centra, navigate to **System**, then **Configuration**, click **Create attribute type**
and add `ge_variant_data` (**Global-E Variant Information**) using the definition below.
```
{
"desc": "Global-E Variant Information",
"readonly": false,
"group": "variation",
"elements": {
"mid_identifier": {
"type": "input",
"desc": "Global-E Manufacturer Product Code"
}
}
}
```
2. **Populate the values per variant.** Open the product, navigate to the **Variants** tab and click on the variant name, then **Custom attributes**. On each variant, fill Global-E Manufacturer Product Code when you have a value to send.
3. **DTC merchants only:** navigate to **Platform**, then **Stores management**, then **Stores**,
open your store, then **Plugins**, then **DTC API**, then **View**.
Under **Display item attributes**, search `global-e variant` and select **Global-E Manufacturer Product Code**
then click **Save.**
Checkout API merchants skip this step.
4. **Place a test order** and confirm the values appear when populated and are omitted when blank.
| Sent as | What it holds | When to leave it out |
| - | - | - |
| **`standardcode`** | The barcode for that size, read from the native GTIN (DTC) or EAN (Checkout API) field in Centra | When the native barcode field is empty — the key is omitted automatically. |
| **`mididentifier`** | The manufacturer's product code for that variant | Never. This is required on every line. |
Where `standardcode` comes from
| API | Source |
| - | - |
| DTC (GraphQL) | Native **GTIN** field on each size/item in Centra. Populated via your ERP or PIM integration. |
| Checkout API | Native **EAN** field on each size in Centra. Visible in the product editor under **Variants →** Manage Stock → Size Info. |
No custom attribute configuration is required for `standardcode`. If the native field is empty, the key is omitted automatically.
**EAN field location in Centra**
EAN is entered per size under Manage Stock → Size Info on each product variant in Centra.
## Key points
**One pair of values per variant.** Populate each variant that can appear in the cart. A value on the parent product alone is not enough when the variant has no value of its own.
In Centra you see Global-E Manufacturer Product Code under Custom attributes on the variant. The integration maps it to `mididentifier` (lowercase) at checkout. `standardcode` is mapped automatically from the native barcode field — no custom attribute needed.
**The catalog setup is the same for DTC (GraphQL) and Checkout API.** DTC has one extra step: select Global-E Manufacturer Product Code under store, **DTC API**, **Display item attributes**, then **Save**.
**Omit, don't fake.** When a variant has no value, leave it blank. Never enter an empty placeholder such as NA, 0 or -.
**When values are read:** at checkout. Updated variant values apply on that SKU's next checkout.
Quick check before go-live
| Check | Done |
| - | - |
| `ge_variant_data` attribute type created | ☐ |
| Global-E Manufacturer Product Code populated on each variant | ☐ |
| Native EAN (Checkout API) or GTIN (DTC) filled for each size in Centra | ☐ |
| `standardcode` and `mididentifier` appear in SendCart when values exist | ☐ |
| Keys omitted (not empty) when a variant has no value | ☐ |
| Each variant in the cart sends its own pair | ☐ |
| DTC only: **Global-E Manufacturer Product Code** selected under store, **DTC API**, **View**, and saved | ☐ |
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