# ISO 6523

International standard that registers identifier schemes for organisations — the foundation of the EAS code list.

## Definition

International standard that registers identifier schemes for organisations — the foundation of the EAS code list.

## Explanation

Each scheme is referenced by a numeric ICD (International Code Designator); GS1 GLN is ICD 0088, GS1 SSCC is 0008, German VAT-ID is 9930.

Maintained by the ICD Registration Authority; new schemes are added by national bodies and indirectly drive Peppol participant identifiers.

## Related resources

- [Code lists](/resources/code-lists)

## Related terms

- [EAS (Electronic Address Scheme)](/resources/glossary/eas): EN 16931 code list (CEF EAS) that says which identifier scheme — VAT-ID, GLN, OIN, etc. — is used for an electronic address.
- [GLN (Global Location Number)](/resources/glossary/gln): GS1 13-digit identifier for a legal entity, function, or physical location — the standard EAS scheme 0088 in EN 16931.
- [D-U-N-S Number](/resources/glossary/duns): Dun & Bradstreet 9-digit identifier for legal entities, common in international procurement and ISO 6523 ICD 0060.
- [Participant ID](/resources/glossary/participant-id): Identifier used in PEPPOL to address a sender/receiver (e.g., with a scheme).