An LEI, Legal Entity Identifier, is a code used for unique identification of legal entities. Any legal entity having had an LEI issued is represented in the Global LEI System, which is a public register common for all jurisdictions worldwide. The register is supervised by the Global Legal Entity Identifier Foundation, 'GLEIF', and was initially an initiative by the G20 countries.
A legal entity can only have one LEI issued. Below you can see an example of an LEI.
NordLEIs LEI: 549300O897ZC5H7CY412