What Does UEI Stand For? Unique Entity ID Meaning
UEI stands for Unique Entity ID — the 12-character government-issued identifier that replaced DUNS for every federal contractor and grant applicant. Here's what it means.
UEI stands for Unique Entity ID. It is the 12-character alphanumeric identifier that the U.S. federal government assigns to every organization that does business with it — contractors, grant recipients, nonprofits, and state and local governments. Issued for free through SAM.gov, the UEI replaced the DUNS number on April 4, 2022 as the government's official way to identify a legal entity.
If you have ever seen "UEI" on a federal solicitation, a grant application, or a SAM.gov record and wondered what it means, this is the short answer — and below is everything that sits behind it.
What the term "Unique Entity ID" actually means
Break the name down and it explains itself:
- Unique — no two organizations share a UEI. It maps one-to-one to a single legal entity.
- Entity — a legal organization (your company, nonprofit, or government office), not a person and not a single contract.
- ID — an identifier, the way an EIN identifies you to the IRS or a VIN identifies a car.
So a Unique Entity ID is simply the one number the federal government uses to recognize your organization across all of its systems. Whenever a federal system needs to know "who is this?", the answer is your UEI.
What a UEI looks like
A UEI is 12 characters, a mix of letters and numbers, with no dashes or spaces — for example ABC123DEF456. It deliberately avoids the letters O and I and never starts with a zero, so it can't be confused with other codes. For a full breakdown of valid and invalid examples, see UEI number format.
Why "UEI" suddenly appeared everywhere
Until April 2022, the federal government identified entities using the DUNS number, a nine-digit code licensed from the private company Dun & Bradstreet. Congress directed the government to stop paying a vendor for something it could issue itself, and GSA built the UEI as a government-owned replacement. On April 4, 2022 the switch flipped: DUNS was retired federally and the UEI took over.
That is why the acronym showed up on forms, contracts, and grant portals seemingly overnight. It wasn't a new requirement so much as a renamed and re-homed one. For the full history and migration details, read Unique Entity ID (UEI) explained.
Is "UEI" the same as "SAM UEI" or "SAM.gov number"?
Yes. People search for "SAM UEI," "SAM.gov number," and "unique entity identifier" — they all refer to the same 12-character UEI. It's called the "SAM UEI" only because SAM.gov is the system that issues and stores it. There is no separate "SAM number."
You may still hear "unique entity identifier" (with an -er) used interchangeably with "unique entity ID." Officially it's "Unique Entity ID," but the meaning is identical.
Where you'll see and use your UEI
Once assigned, your UEI follows you through the entire federal lifecycle:
- SAM.gov registration — displayed on your entity record
- Proposals and bids — federal forms like the SF-33 have a dedicated UEI field
- Grant applications — required on Grants.gov submissions
- Invoices and payments — payment systems key on it
- Capability statements — list it alongside your CAGE code and NAICS codes
How to find or get yours
- Already registered? Look up your UEI — it's on your SAM.gov record and is public.
- No SAM.gov record yet? Follow how to get a UEI number. It's free and assigned automatically during registration.
Frequently asked questions
What does UEI stand for? Unique Entity ID — the 12-character identifier the U.S. government assigns to organizations through SAM.gov.
What does UEI mean on a contract or grant? It's the field where you enter your organization's Unique Entity ID so the agency can match the award to your verified SAM.gov record.
Is the UEI the same as a DUNS number? No. The UEI replaced DUNS for all federal purposes on April 4, 2022. DUNS still exists as a private commercial identifier but has no federal role.
Does a UEI cost anything? No. The UEI is free and issued by the government as part of SAM.gov registration. Avoid any third-party service that charges to "get your UEI."
Key takeaways
- UEI = Unique Entity ID, a free, 12-character, government-issued identifier.
- It replaced DUNS for all federal contracting and grants on April 4, 2022.
- "SAM UEI," "unique entity identifier," and "UEI" all mean the same thing.
- You get it — and find it — through SAM.gov, never from a paid third party.