Unique Entity Identifier (UEI)
A 12-character identifier assigned by SAM.gov to every entity registered to do business with the US federal government. Replaced the DUNS number in April 2022.
Definition
The Unique Entity Identifier is a 12-character alphanumeric (case-insensitive) ID generated automatically when an entity completes SAM.gov registration. It replaced the Dun & Bradstreet DUNS number that the federal government previously used.
When it applies
Required for any entity bidding on federal contracts, applying for federal grants, or being paid as a subcontractor on a federal prime contract. The UEI stays with the entity for its life — it does not change with ownership transfers or address moves. Existing DUNS-numbered entities active in SAM.gov at the time of the transition were assigned a UEI automatically.