Unique Entity Identifier (UEI)

Definition

The Unique Entity Identifier (UEI) is a 12-character alphanumeric identifier generated and managed by SAM.gov. It replaced the DUNS number in April 2022 as the federal government's required entity identifier. Every SAM.gov registration receives a UEI during entity validation; the UEI is used across FPDS, grants systems, assistance programs, and payment systems. Unlike DUNS, which was controlled by Dun & Bradstreet, the UEI is entirely under government control, eliminating licensing concerns for third-party systems.

Why It Matters

Without a valid UEI, your firm cannot register, propose, or be paid on federal contracts. Verifying your UEI in every proposal, invoice, and communication with the government is basic hygiene. Firms that went through the legacy DUNS-to-UEI transition still occasionally hit issues where old systems reference the DUNS; maintaining a clear record of both identifiers prevents surprises.

Example

A firm submits a proposal with its UEI on the cover page, in the SF 33 representations, and in its SAM.gov entity profile. After award, its invoices reference the UEI and the CAGE code, processed cleanly by DFAS.

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