GovCon API
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DUNS ↔ UEI Crosswalk

Paste a legacy 9-digit DUNS or a current 12-character UEI. Get back the other identifier and the entity name from our FFATA-derived crosswalk of 24,217 federal contractors.

Case-insensitive. Dashes and DUNS+4 suffixes are stripped automatically.

Try a known case:
Vendor master migration

Stranded DUNS in your AP / 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.

Compliance & audit

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.

Research & BD

Joining historical FPDS data

Pre-2022 FPDS records carry DUNS. Post-2022 records carry UEI. To trace one vendor's full federal history you need both; this crosswalk is the bridge for any contractor that shows up in FFATA filings.

Top 25 indexed pairs

The pairs with the most FFATA subaward filings linking the two identifiers. High evidence count means an actively-transacting federal contractor with a deep paper trail. Click a DUNS to look up its pair.

Entity DUNS UEI Evidence
LA PLAYA INC OF VIRGINIA 110899747 THG6P85GNET9 1288
CARAHSOFT TECHNOLOGY CORP 088365767 DT8KJHZXVJH5 1049
STERLING COMPUTERS CORPORATION 938836541 YZTLALWM4UC7 871
WORLD WIDE TECHNOLOGY LLC 614948396 C8VFSNKTMQB6 674
CDW GOVERNMENT LLC 026157235 PHZDZ8SJ5CM1 644
DELL FEDERAL SYSTEMS L.P 149530219 N1C5QLNPJLS4 618
THUNDERCAT TECHNOLOGY, LLC 809887164 UER4AJLUB8D5 448
ADVEX CORPORATION 046974937 JM2GNDJLDWL5 425
CUMING MICROWAVE CORPORATION 187336503 L672EKM4WCC5 415
TTI INC. 057421000 U6JRN865H4E3 364
AAR COMPONENT SERVICES - HOT SPRINGS, LLC. 958361438 VYD1X5MNSKB3 334
CATERPILLAR INC 944204924 C9C6HPQLL4A8 333
GOVSMART, INC. 961600272 DJACUETFQUL8 327
GLENAIR, INC. 008385312 YVBHN7GKLQ44 307
AVNET INC 006995419 J8WCYWJQKJE9 296
FCN, INC. 615378007 JEANDJTZ8HJ3 294
TEVET LLC 149433844 CQLFMKPGRUQ3 271
TRIDENT MARITIME SYSTEMS, INC. 065377202 JMLPPDXERGK4 261
GENERAL DYNAMICS LAND SYSTEMS - CANADA CORPORATION 201756876 UKN6CJ49WB54 249
INSIGHT GLOBAL, LLC 961928400 LW88Z8MMJHT3 246
ALLISON TRANSMISSION INC 804407463 CBQZMN7QV9N5 233
AMERICAN SCAFFOLD LLC 123633666 K1YLLHBBMPT1 229
CTG FEDERAL, LLC 080932836 G2D4Q7UKR5P5 223
MAIN INDUSTRIES, INC. 085128452 EJB6ZB4NKGJ7 223
HAMILTON SUNDSTRAND CORPORATION 071767334 JC42EBJ5NFJ1 221

No pagination. Top 25 are the proof; search any individual identifier above or hit the API for programmatic access.

Same lookup via API (free)

One endpoint, either side of the pair, same shape. Free tier. An API key is required only so we can track usage and prevent abuse. Get a free key →

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. See Coverage below for the honest scope.

Coverage truth

This is a FFATA-derived crosswalk, not the full SAM registry. The 24,217 pairs indexed here are entities that have appeared in FFATA Section 2 subaward filings since FY2025 with both their legacy DUNS and 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 sub-contractors and primes from FY2025 onward, including most recognizable defense / IT integrators (Carahsoft, World Wide Technology, Dell Federal, CDW-G, Sterling Computers) plus thousands of smaller subcontractors.

What this misses. Entities that haven't 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; entities whose registrations migrated to UEI long before FY2025 and have not had 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↔UEI translator is admin-gated and not publicly available. Major free third-party UEI lookups accept company name / UEI / CAGE but not DUNS. This page exploits the fact that FFATA filings preserved the side-by-side mapping for the population that has filed (or had filed 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, the differences below are what you need to know to migrate.

Attribute DUNS (legacy) UEI (current)
IssuerDun & Bradstreet (private)SAM.gov (federal, internal)
Length9 digits (numeric)12 characters (alphanumeric)
CostFree for entity holder, federal licensing fee paid by GSAFree, no third-party licensing
Federal statusRetired as primary key on 4 April 2022Current and only federal entity identifier
Accepted in SAM APINo (field is empty in API responses)Yes (primary key for all entity queries)
DUNS+4 equivalentDUNS + 4-digit sub-location suffixSingle UEI per location; no equivalent suffix
Non-federal useStill issued and used in credit reporting, supplier risk, private procurementUS 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. 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; you do not need this lookup. A 5-character alphanumeric value is a CAGE code; use the CAGE code lookup instead.

  2. 2

    Paste the DUNS into the lookup

    Enter the DUNS in the search box at the top of this page and submit. The lookup runs against the FFATA-derived crosswalk of 24,217 federal contractors. Dashes and DUNS+4 suffixes are stripped automatically before the search.

  3. 3

    Confirm the match against sam.gov

    When the lookup returns a UEI, click the Verify on sam.gov link to cross-check entity name, address, and registration status. The crosswalk reflects FFATA filings, not real-time SAM state, so always verify before relying on it for compliance or procurement decisions.

  4. 4

    Pull the full SAM record (optional)

    With the UEI in hand, fetch the full SAM registration with GET /api/v1/entities/{uei}: legal name, NAICS, certifications, CAGE codes, contact, address, registration status. Or screen the UEI against the federal exclusions list with GET /api/v1/exclusions/{uei} (free).

Frequently asked questions

DUNS retirement, UEI mechanics, and lookup caveats.

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. This page does the lookup at no cost, no account required. 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, paste your DUNS into the lookup at the top of this page. (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. The evidence count next to each result shows how many filings 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

UEI Lookup API
Full SAM registration record for a UEI: legal name, NAICS, CAGE, certifications, address. Developer tier.
CAGE Code Lookup
DoD 5-character identifier to federal contractor record. Same shape as UEI lookup. Developer tier.
Vendor Risk Lookup (Free)
Exclusion status, address-cluster signals, name-variant matches for any SAM UEI. No account.
Federal Contractor Search
Search 873K federal contractors by name, NAICS, state, certification, active status.
Federal Subawards API
The dataset this crosswalk is derived from. Full FFATA Section 2 subaward records since FY2025.
Agency Crosswalk (Free)
Standardize federal agency names across SAM, USAspending, FPDS variants. No account.

Crosswalk derived from public FFATA subaward filings (USAspending). A 404 here is not a SAM 404. For per-record SAM registration detail by UEI, see /api/v1/entities/{uei}. Last updated 2026-05-31; refresh cadence follows the FFATA subaward ingestion pipeline.