United States · Federal contracting identifiers
SAM.gov UEI validator.
Check that a Unique Entity ID has the published shape: 12 letters and digits, never the letters I or O, and never a zero in the first position.
The rules this tool applies: exactly 12 characters, letters and digits only, no I and no O, and the first character is not 0. Case does not matter.
How to check a UEI
- Type or paste the value. Spaces and hyphens are ignored and case does not matter.
- Press Check.
- Read the result: either the normalized value, or the exact rule it breaks.
Your input stays on your device
The check runs in your browser, inside an isolated frame on this page that has no network access. Nothing you type is uploaded to TNAADO or anyone else, and nothing is stored. The advertising on this page sits outside the frame and cannot see what you enter.
What the UEI rules say
The Unique Entity ID (UEI) is the identifier SAM.gov assigns to entities that register to do business with the US federal government. GSA's Unique Entity ID stakeholder FAQ (November 2021) states the format in three sentences: the identifier is a 12-character alphanumeric value, the letters O and I will not be used to avoid confusion with zero and one, and the first character will not be zero, to avoid digits being cut off when data is imported into spreadsheet programs.
Those three published rules are what this page enforces. A value that fails one of them cannot be a real UEI, so catching it before you paste it into a grant portal, a contract form or a vendor-onboarding sheet saves a rejected submission. A value that passes has the right shape and nothing more.
GSA's technical specification page may define further details of the identifier. This tool does not attempt to verify anything beyond the three rules above, so a typo that happens to produce another well-shaped string will still pass.
Worked example (made-up value): J6H4FB3N5YK4 is 12 characters, uses only letters and digits, contains no I or O, and starts with J, so it passes. J6H4FB3N5YKO fails because it contains the letter O. 06H4FB3N5YK4 fails because it starts with zero. An 11- or 13-character value fails on length.
Method
The check is a fixed set of format rules applied to the text you type, after upper-casing it and removing spaces and hyphens. There is no database, no estimate and no assumption about who you are: the same input always gives the same answer, and every rule is traceable to the sources below.
What this does not cover
- Whether the UEI was ever issued or whether the entity's SAM.gov registration is active. Search SAM.gov for that.
- Any rule beyond the three published ones above, including any check character GSA may define in its technical specification.
- Older identifiers: a nine-digit number is not a UEI.
- The separate four-character EFT indicator that SAM.gov uses for bank accounts.
Frequently asked questions
How long is a SAM.gov UEI?
Twelve characters, letters and digits. The SAM Functional Data Dictionary lists the field as alphanumeric with length 12.
Why do UEIs never contain the letters I or O?
GSA says they are left out to avoid confusion with the digits 1 and 0.
Can a UEI start with zero?
No. GSA says the first character is never zero so digits are not cut off in spreadsheet imports.
Does this confirm my SAM.gov registration?
No. It checks the shape only. Look the entity up on SAM.gov to confirm registration status.
Sources
- GSA, Unique Entity ID (SAM) Stakeholder Forum FAQs, Nov 3 2021 (retrieved 2026-10)
- SAM Functional Data Dictionary, June 23 2023 (UEI: alphanumeric, length 12) (retrieved 2026-10)
- FAR 52.204-6, Unique Entity Identifier (retrieved 2026-10)
Shape only
A correctly formatted value is not proof that an identifier was issued, is active or belongs to the person or business in front of you. Confirm with the issuing agency. This page is general information, not legal, tax or compliance advice.