A legal entity identifier is an internationally standardized (ISO 17442) identifier for entities that engage in financial transactions. Consisting of 20 alphanumeric characters, each string is a structured code with check digits at the end. It can be applied to individual persons as well as businesses or other entities.

The first four characters identify the local operating unit that issued it, the next two are always zeros, twelve identify the entity, and the last two are the check digits. The check makes a mistyped value detectable without a lookup.

The system was set up after the 2008 financial crisis, when regulators could not tell which entities in a group were counterparties to which trades. It is administered globally by the Global Legal Entity Identifier Foundation through accredited issuers.

An identifier has to be renewed each year and lapses if it is not, so a record can exist while its status reads as lapsed. The number stays with the entity either way and is never reissued to another.