DUNS Number to UEI Transition: What Contractors Need to Know
The federal government's shift from the DUNS Number to the Unique Entity Identifier (UEI) represents the most significant change to contractor registration infrastructure in more than two decades. This page explains what each identifier is, how the transition was executed, the practical scenarios contractors encounter in the post-transition environment, and the boundaries that determine when a new UEI is required versus when an existing one carries forward. Contractors working with SAM Registration Requirements or maintaining active registrations in SAM.gov need to understand this change to avoid lapses in award eligibility.
Definition and Scope
The DUNS Number (Data Universal Numbering System) was a 9-digit proprietary identifier issued by Dun & Bradstreet (D&B), a private commercial entity. Federal agencies used the DUNS Number as the primary means of identifying contractors and grant recipients in federal procurement systems for roughly 30 years. Because the identifier was owned and managed by a private company, the federal government paid licensing and data-management fees to D&B for access to the system.
The Unique Entity Identifier (UEI) is a 12-character alphanumeric identifier assigned and managed directly by the General Services Administration (GSA) through SAM.gov. The UEI eliminates the federal government's dependency on a proprietary third-party system and consolidates entity identification within the federal ecosystem.
The formal transition was governed by a rule published in the Federal Register by the Office of Management and Budget (OMB) and GSA. As documented by SAM.gov and GSA, April 4, 2022 was the date on which the DUNS Number ceased to be accepted for federal award transactions. From that date forward, the UEI became the sole accepted entity identifier across all federal procurement and assistance programs covered by the Federal Acquisition Regulation and the Uniform Guidance (2 CFR Part 200).
Scope covers:
- All entities registering in SAM.gov for federal contracts
- Grant recipients and subrecipients subject to 2 CFR Part 200
- Entities reporting in FSRS (Federal Subaward Reporting System)
- Entities appearing in USASpending.gov
How It Works
GSA's transition mechanism was designed to avoid requiring contractors to take manual action to receive a UEI. For the approximately 750,000 entities that held active SAM.gov registrations at the time of transition, GSA auto-assigned a UEI to each existing record. The auto-assigned UEI was made visible in each entity's SAM.gov profile before the April 2022 cutover date, allowing contractors to capture and communicate the new identifier to agency contracting officers in advance.
The assignment logic works as follows:
- Existing active registrations — A UEI was auto-generated and mapped to the existing SAM.gov record. The entity's DUNS Number remained visible in the profile as a legacy reference field but lost its functional role in award transactions.
- New registrations (post-April 2022) — Entities registering for the first time receive a UEI at the point of registration. No DUNS Number is generated or required as part of the process.
- Expired or lapsed registrations — Entities with registrations that had expired prior to the transition must renew their SAM.gov registration to reactivate, and the UEI becomes the active identifier upon renewal.
- Subcontractors without SAM registration — Entities that are only required to obtain a UEI (without full SAM registration, e.g., certain FSRS reporting contexts) can request a UEI through SAM.gov without completing the full registration process.
The UEI is tied to the legal business name and physical address on record in SAM.gov. Unlike the DUNS system — where D&B assigned identifiers based on its own commercial database — the UEI is issued solely on the basis of the SAM.gov registration record, which the entity itself controls and certifies.
Common Scenarios
Scenario 1: Existing prime contractor with active SAM registration
A contractor registered in SAM.gov before April 2022 and maintaining continuous annual renewals already has a UEI. The UEI appears in the entity's SAM.gov profile. No additional action was required for the identifier itself, though the contractor must communicate the UEI — not the DUNS Number — on all solicitation responses, invoices, and reporting submissions. Contracting officers referencing the Contracting Officer Role will reject award documentation that references a DUNS Number in lieu of a UEI.
Scenario 2: New contractor entering the federal market
An entity pursuing its first federal contract registers in SAM.gov and receives a UEI automatically as part of that process. There is no separate application, no D&B interaction, and no fee. The UEI is available within the SAM.gov registration record immediately upon assignment.
Scenario 3: Subcontractor required to report in FSRS
A subcontractor receiving subawards above the reporting threshold may need a UEI without needing a full SAM.gov registration. That entity can navigate to SAM.gov and request a UEI-only assignment. This scenario is distinct from a prime contractor registration and does not confer award eligibility by itself.
Scenario 4: Lapsed registration
A contractor whose SAM registration expired before the transition cutover must complete a full SAM.gov registration renewal. Upon renewal, a UEI is assigned. Awards cannot be made to entities with expired SAM registrations regardless of whether a DUNS Number previously existed in agency systems. See SAM Registration Requirements for renewal procedures.
Decision Boundaries
The key distinction contractors must understand is the difference between identifier assignment and registration status. These are related but separate concepts:
| Condition | UEI Exists? | SAM Registration Active? | Award Eligible? |
|---|---|---|---|
| Active SAM registration, post-transition | Yes | Yes | Yes |
| Active SAM registration, pre-transition (auto-assigned) | Yes | Yes | Yes |
| UEI-only request (no full registration) | Yes | No | No |
| Expired SAM registration | Yes (legacy) | No | No |
| New entity, not yet registered | No | No | No |
A second boundary governs when a new UEI is required versus when an existing one carries forward:
- Legal name or structure change (e.g., merger, acquisition, name change) typically requires updating the SAM.gov record. Depending on the nature of the change, a new UEI may be assigned. GSA's SAM.gov help documentation addresses this on a case-by-case basis, but the general rule is that a new legal entity requires a new registration and therefore a new UEI.
- Address change or administrative update does not trigger a new UEI. The UEI persists through updates to the existing record.
- Expiration and renewal of an existing registration does not generate a new UEI. The same UEI is reactivated upon renewal.
The Unique Entity Identifier page on this reference network provides additional detail on UEI structure and its role in the broader federal contracting ecosystem. Contractors exploring the full landscape of registration and compliance obligations can find an entry point at the Government Contractor Authority index.
For contractors tracking downstream compliance implications — including how UEI assignment intersects with DFARS Compliance or Subcontracting Plans Requirements — the UEI serves as the anchor identifier throughout the entire contract lifecycle, from solicitation response through Contract Closeout Procedures.