DUNS Number (Legacy)

The DUNS Number was the standard business identifier for federal procurement for nearly three decades. It appears on millions of historical contract records, grant applications, and subcontracting reports, making it essential to understand when researching older award data even though it is no longer used for new applications.

What is a DUNS Number?

DUNS stands for Data Universal Numbering System. Dun and Bradstreet developed the nine-digit identifier in the 1960s for commercial credit reporting, and the federal government adopted it as the mandatory entity identifier for procurement and grants beginning in the early 1990s. Every company, nonprofit, university, or government entity that registered in SAM.gov (or its predecessor systems) received a DUNS Number from D&B, which maintained its own registration database separate from the federal systems. The identifier linked a legal entity's name, address, and corporate structure to its federal award history in FPDS-NG and USASpending. As of April 4, 2022, the federal government retired the DUNS Number in favor of the UEI generated directly within SAM.gov, ending the third-party D&B dependency. Historical records in FPDS-NG and USASpending still display DUNS Numbers for awards made before 2022.

Why DUNS Numbers matter for government contractors

Although DUNS Numbers are no longer accepted for new registrations or awards, they remain important for competitive intelligence. Historical award data in USASpending and FPDS-NG from before April 2022 is indexed by DUNS Number. Contractors researching a competitor's historical contract wins, or reviewing their own historical records, will encounter DUNS Numbers throughout those older datasets.

Example

A contractor uses USASpending to research an incumbent's contract history with the Army Corps of Engineers. Awards from 2018 through 2021 are indexed under the incumbent's DUNS Number. Awards from 2022 onward appear under the UEI. Both identifiers are displayed in the award records, so the search returns the complete history.

Frequently Asked Questions

Can I still use my DUNS Number for new federal registrations?

No. Since April 4, 2022, only the UEI is accepted for SAM.gov entity registration and federal award applications. The DUNS Number is retired for this purpose.

Will old contracts awarded under a DUNS Number be affected?

No. Existing contracts that were awarded using a DUNS Number continue normally. The identifier change was purely for new registrations and awards.

How do I find the UEI that replaced my old DUNS Number?

Log into SAM.gov. The entity record displays the UEI that replaced the DUNS Number when the migration occurred. USASpending also cross-references both identifiers for the transition period.

Did all DUNS Numbers convert to UEIs automatically?

Yes. For entities with active SAM.gov registrations at the time of the transition, SAM.gov automatically generated a corresponding UEI. Companies did not need to reapply.

Why did the government move away from DUNS Numbers?

The primary reasons were cost and control. D&B charged fees for some services and maintained a separate commercial database. Generating identifiers within SAM.gov directly eliminated third-party dependency, reduced costs, and gave the government full control over the identifier namespace.