Identifiers

Every credential in DPP Kit is assigned a globally unique identifier following GS1 standards. These identifiers allow products and facilities to be looked up by scanning a barcode, QR code, or querying a resolver.

Identifier Types

Identifier	Format	Used By	Example
GLN-13	13 digits	DFR, DIA	9347823000012
GTIN-14	14 digits	DPP, DTE, DCC	09347823000029

How Identifiers Are Generated

Each organization is assigned a unique 7-digit prefix at registration (e.g., 9347823). Identifiers are then built as follows:

GLN-13 (Facilities)

┌─────────────┬──────────┬─────────────┐
│ Org Prefix  │ Counter  │ Check Digit │
│ 7 digits    │ 5 digits │ 1 digit     │
└─────────────┴──────────┴─────────────┘
Example: 9347823 00001 2

GTIN-14 (Products)

┌──────────┬─────────────┬──────────┬─────────────┐
│ Indicator│ Org Prefix  │ Counter  │ Check Digit │
│ 1 digit  │ 7 digits    │ 5 digits │ 1 digit     │
└──────────┴─────────────┴──────────┴─────────────┘
Example: 0 9347823 00002 9

The check digit is calculated using the GS1 mod-10 algorithm (per ISO/IEC 7064).

Identifier Options When Issuing

When creating a DPP credential, you have three options:

1. Auto-generate — DPP Kit generates the full GTIN-14 automatically using your org prefix and an incrementing counter
2. Provide a SKU — Enter your product SKU and DPP Kit generates a GTIN-14 incorporating it
3. Bring your own GTIN — Enter a GTIN-14 you already have from a GS1 Member Organization

tip

For pilots, auto-generated identifiers are the fastest way to get started. When you move to production, you can bring your own GS1-assigned identifiers.

Serialization

Beyond the base identifier, products can be tracked at batch and serial granularity using GS1 Application Identifiers:

AI	Name	Path	Example
01	GTIN	/01/{gtin}	/01/09347823000029
10	Batch	/01/{gtin}/10/{batch}	/01/09347823000029/10/LOT-A
21	Serial	/01/{gtin}/10/{batch}/21/{serial}	/01/09347823000029/10/LOT-A/21/001

These paths are registered in the Identity Resolver so scanning a QR code leads directly to the credential.