LEI Structure

What an LEI is

The LEI (Legal Entity Identifier) is a 20‑character code used to uniquely identify legal entities participating in financial transactions. It is defined by ISO 17442.

20-character composition (high level)

• Characters 1–4: LOU identifier (the issuer).
• Characters 5–6: reserved (typically 00).
• Characters 7–18: entity-specific identifier.
• Characters 19–20: check digits.

Basic checks you can perform

• Length is 20 characters.
• Allowed character set (digits and uppercase letters excluding certain ambiguous letters).
• Check digits are present (validation requires the standard algorithm).

Operational note

LEI status (issued, lapsed, retired) is maintained in LEI data services. Structural validity does not guarantee an LEI is active.

Related pages

LEI verification overview | When to use VAT vs EORI vs LEI