What Is a UEI (Unique Entity ID)?

Definition

The Unique Entity ID is the federal government's standard identifier for an organization registered to do business with it. It is twelve characters, alphanumeric, and assigned through SAM.gov when an entity registers. Each registered entity has its own UEI, which makes it a precise way to refer to a specific business even when two companies share a similar name.

Why it replaced the DUNS number

For years the government used the DUNS number, a proprietary identifier managed by a third party. The federal government transitioned to the government-owned UEI to remove dependence on a proprietary system and to consolidate entity identification within SAM.gov. If you have older records that reference a DUNS number, the corresponding entity now has a UEI instead.

Where you will see a UEI

• On an entity's SAM.gov registration.
• On federal award records in USAspending.gov.
• On contract documents and reporting that identify the recipient.

How to use a UEI for lookups

Because a UEI maps to exactly one registered entity, it is the most reliable starting point for a lookup. If you have a UEI, you can go straight to that entity's profile and its award history without worrying about name collisions. If you only have a company name, finding the UEI first makes every later step more accurate.

Common points of confusion

A UEI is not a CAGE code, a tax ID, or a contract number. It identifies the entity, not a specific award or location. A single entity with one UEI can hold many awards and may have one or more CAGE codes tied to its locations.

How the UEI is formatted

A UEI is twelve characters drawn from letters and digits. It is assigned by SAM.gov rather than chosen by the entity, so it carries no embedded meaning — you cannot read a company's size, location, or industry from the characters. Because it is a single fixed-length token, it is easy to store, compare, and search exactly, which is one reason it is so useful for matching records across systems.

When you copy a UEI, copy all twelve characters and avoid transcription errors — a single wrong character points to a different entity or to nothing at all. If a UEI you were given does not resolve, re-check it character by character before assuming the entity does not exist.

Why entity-level identity matters

Names are ambiguous and change; identifiers are not. A business may rebrand, operate under a 'doing business as' name, or share a common word with dozens of unrelated firms. The UEI cuts through that ambiguity by naming one registered entity precisely. For anyone aggregating or comparing federal activity — researchers, analysts, lenders, or buyers — anchoring on the UEI is what makes the analysis reliable rather than a guess based on name matching.

From UEI to insight

• Pull the entity's full award history without name-collision noise.
• See which agencies it works with and how concentrated that work is.
• Compare its NAICS and PSC mix against peers in the same space.
• Cross-reference the same UEI in the official systems for registration status.

What the UEI does not tell you

The UEI identifies who, not how much or how well. It does not encode award totals, financial health, performance quality, or registration status — those live in the award records and in SAM.gov. Treat the UEI as the reliable key that unlocks those other facts, not as a fact in itself.

The transition from DUNS, in practice

If you work with older records, you will still encounter the DUNS number — the proprietary identifier the government used before the UEI. The move to the UEI consolidated entity identification inside SAM.gov and removed the dependence on a third-party system. In practical terms, an entity that once had a DUNS number now has a UEI, and modern award and registration records key off the UEI. When you reconcile historical data, expect to map old DUNS-based records to current UEIs rather than finding DUNS numbers in new records.

Tips for working with UEIs at scale

• Store the UEI as the primary key when aggregating an entity's activity.
• Validate format (twelve alphanumeric characters) before trusting a value.
• De-duplicate on the UEI, not the name, to avoid double-counting similar names.
• Keep the legal name alongside the UEI for human-readable display and sanity checks.

Parent companies and related entities

Large organizations are not always a single registered entity. A corporate parent may have several subsidiaries, divisions, or affiliated entities, each registered separately with its own UEI. That means a company you think of as one business can show up under multiple UEIs, and a complete picture of its federal footprint may require gathering several of them. When you research a large recipient, check whether related entities exist and decide whether your analysis should treat them separately or roll them up. The UEI keeps each entity distinct, which is exactly what you want when precision matters, but it also means you are responsible for deciding where one organization ends and another begins.

Frequently asked questions