DUNS to UEI Crosswalk

The legacy 9-digit DUNS and the current 12-character UEI, matched to the same entity. The crosswalk holds about 24,000 federal contractors, drawn from FFATA subaward filings since FY2025.

Who uses this

Stranded DUNS in your AP or ERP

Your procurement system stored contractor IDs as DUNS before April 2022. Nothing in SAM accepts a DUNS as input anymore. Resolve them to UEIs to keep the integration working.

Reconciling pre-2022 records

Audit datasets, FCA case files and compliance archives reference contractors by DUNS. Map them to UEIs before re-screening against the current SAM exclusions list.

Joining historical FPDS data

Pre-2022 FPDS records carry DUNS and post-2022 records carry UEI, so tracing one vendor's full federal history needs both. This crosswalk is the bridge for any contractor that shows up in FFATA filings.

The same lookup from the API

One endpoint, either side of the pair, the same response shape. It is included on every plan, and a key is required only so we can attribute usage and stop abuse, so you can get one free.

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://govconapi.com/api/v1/identifiers/110899747"

# or by UEI:
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://govconapi.com/api/v1/identifiers/THG6P85GNET9"

A 404 means the identifier is not in the FFATA-derived crosswalk, and the scope of that is under Coverage truth below.

USAspending resolves a legacy DUNS to its current UEI at /api/v2/recipient/children/{duns}/ on api.usaspending.gov, no key and no account, and GET /api/v1/identifiers/{id} takes either side of the pair and returns both with the evidence count behind them.

Coverage truth

This is a FFATA-derived crosswalk, not the full SAM registry. A pair is indexed when an entity has appeared in a FFATA Section 2 subaward filing since FY2025 with both its legacy DUNS and its current UEI populated on the same record. Subaward filings are the public dataset where the two identifiers ended up side by side.

What this covers well. Active federal subcontractors and primes from FY2025 onward, including most recognizable defense and IT integrators (Carahsoft, World Wide Technology, Dell Federal, CDW-G, Sterling Computers) plus thousands of smaller subcontractors.

What this misses. Entities that have not appeared as a prime-with-DUNS or sub-vendor in FFATA reporting since FY2025; entities active only on contracts below the $30K FFATA reporting threshold; entities active only on contract types not subject to FFATA Section 2 reporting; and entities whose registrations migrated to UEI long before FY2025 with no subaward activity since.

Why this exists at all. SAM retired DUNS as an identifier on April 4, 2022 and replaced it with the UEI. SAM's own DUNS to UEI translator is admin-gated and not publicly available, and the major free third-party UEI lookups accept company name, UEI or CAGE but not DUNS. This page uses the fact that FFATA filings preserved the side-by-side mapping for the population that has filed, or had filings made against them, since.

DUNS vs UEI: what changed

If you maintain a vendor master, an audit dataset, or anything else that referenced contractors by DUNS before April 2022, these are the differences that matter to the migration.

Attribute	DUNS (legacy)	UEI (current)
Issuer	Dun & Bradstreet (private)	SAM.gov (federal, internal)
Length	9 digits (numeric)	12 characters (alphanumeric)
Cost	Free for the entity holder, federal licensing fee paid by GSA	Free, no third-party licensing
Federal status	Retired as primary key on 4 April 2022	Current and only federal entity identifier
Accepted in SAM API	No, the field is empty in API responses	Yes, the primary key for all entity queries
DUNS+4 equivalent	DUNS plus a 4-digit sub-location suffix	One UEI per location, no equivalent suffix
Non-federal use	Still issued and used in credit reporting, supplier risk and private procurement	US federal contracting only

How to find a UEI from a DUNS

Four steps from a stranded 9-digit DUNS to a verified 12-character UEI plus the full SAM registration record.

1. Confirm the identifier shape. Verify you have a 9-digit numeric DUNS (or a 13-digit DUNS+4). A 12-character alphanumeric value is already a UEI and needs no lookup, and a 5-character alphanumeric value is a CAGE code, which the CAGE code lookup resolves.
2. Resolve it against the crosswalk. GET /api/v1/identifiers/{id} accepts a DUNS or a UEI and returns both, with dashes and DUNS+4 suffixes stripped before the match.
3. Confirm the match against sam.gov. Search the returned UEI on sam.gov and cross-check entity name, address and registration status. The crosswalk reflects FFATA filings rather than real-time SAM state, so verify before relying on it for a compliance or procurement decision.
4. Pull the full SAM record. With the UEI in hand, GET /api/v1/entities/{uei} returns the full SAM registration: legal name, NAICS, certifications, CAGE codes, contact, address and registration status. To screen the UEI against the federal exclusions list instead, the endpoint is GET /api/v1/exclusions/{uei} and it returns any matching listing.

Frequently asked questions

DUNS retirement, UEI mechanics, and the caveats on this lookup.

What is a DUNS number, and is it still used?

The DUNS (Data Universal Numbering System) is a 9-digit identifier assigned by Dun & Bradstreet. The US federal government used it to identify entities doing business with SAM.gov until April 4, 2022, when it was replaced by the UEI. DUNS still exists for non-federal purposes (credit reporting, private-sector procurement), but no federal API or system accepts DUNS as a primary key today.

What is a UEI?

The Unique Entity Identifier (UEI) is the 12-character alphanumeric identifier SAM.gov assigns to every federal contractor. It replaced the DUNS number on April 4, 2022. The UEI is generated and managed inside SAM.gov; entities do not request it from a third party and there is no annual fee.

Why did SAM replace DUNS with UEI?

GSA moved off DUNS to remove dependency on a single private provider (Dun & Bradstreet) and bring identifier issuance fully inside the federal Integrated Award Environment. UEI is generated by SAM rather than purchased from a vendor, simplifies registration, and eliminates a recurring license cost the federal government was paying for DUNS access.

Can I convert a DUNS to a UEI for free?

Yes, for any entity that has appeared in FFATA Section 2 subaward filings since FY2025. The crosswalk endpoint is included on every plan, including the free key. SAM.gov itself does not publish a public DUNS-to-UEI translator; the official one is admin-gated and limited to federal system accounts. Major free third-party UEI lookup tools (GovBidLab, BidStride) accept company name, UEI, or CAGE code as input but not DUNS.

How do I find my UEI if I only have my old DUNS?

Three paths. (1) If you appeared in FFATA subaward filings since FY2025, GET /api/v1/identifiers/{duns} returns your UEI. (2) Log into SAM.gov with your registered account; your UEI is displayed on the entity record. (3) Contact the Federal Service Desk at 866-606-8220 with your legal business name and old DUNS; they can resolve the UEI from internal records.

What is DUNS+4 and does this lookup support it?

DUNS+4 is the 13-character extended DUNS used to identify sub-locations of an entity that shares one 9-digit base DUNS (the +4 is a 4-digit suffix per sub-location). The base 9-digit DUNS is what maps to a UEI. This lookup accepts 13-digit DUNS+4 input and strips the +4 suffix automatically before searching.

What happens if my entity is not in the crosswalk?

A 404 means the entity has not appeared in FFATA subaward filings since FY2025 with both identifiers populated on the same record. The entity may still exist in SAM under its UEI; this lookup just cannot bridge from your DUNS without an FFATA filing as evidence. Check sam.gov directly using the entity's legal business name to find the UEI manually.

How accurate are the mappings on this page?

Each pair is sourced from FFATA filings submitted by federal prime contractors, where both identifiers are present on the same record. Every response carries an evidence count, the number of filings that carry that exact pair; high evidence counts mean dozens to thousands of independent filings confirm the mapping. Pairs with single-digit evidence counts should be cross-verified against sam.gov before relying on them for compliance decisions.

Is there a bulk DUNS to UEI lookup API?

The free single-record API endpoint is GET /api/v1/identifiers/{duns_or_uei}, rate-limited to 60 requests per minute per IP. Bulk translation of large legacy datasets is on the roadmap; contact us if you need it scoped sooner.

Will the DUNS number be deactivated entirely?

No, DUNS continues to exist as a commercial identifier issued by Dun & Bradstreet for non-federal use cases (credit reporting, supplier risk databases, private sector procurement). It is only retired as the federal entity identifier in SAM.gov. Your DUNS record persists; it just is no longer SAM's primary key.

Related lookups and APIs

Lookup	What it returns
UEI Lookup API	Full SAM registration record for a UEI: legal name, NAICS, CAGE, certifications, address. On every plan
CAGE Code Lookup	DoD 5-character identifier to federal contractor record, the same shape as the UEI lookup. On every plan
Vendor Risk	What a vendor risk screen reads on a SAM UEI: exclusion status, address-cluster signals and name-variant matches. Pro
Federal Contractor Search	What each filter matches when 880K federal contractors are searched by NAICS, state, certification and active status. On every plan
Federal Subawards API	The dataset this crosswalk is derived from: full FFATA Section 2 subaward records since FY2025
Agency Crosswalk	The standard name for an agency across SAM, USAspending and FPDS variants. Free, no key

Crosswalk derived from public FFATA subaward filings (USAspending), so a crosswalk 404 is not a SAM 404. Per-record SAM registration detail by UEI is at /api/v1/entities/{uei}. Last updated 2026-05-31; the refresh follows the FFATA subaward load.