DUNS to UEI crosswalk

Free reverse lookup between a legacy DUNS (9 digits, or 13-digit DUNS+4) and a current UEI (12 alphanumeric). Accepts either side and returns both, plus the entity name and an FFATA evidence count.

Path parameter

• identifier (path): a 9-digit DUNS, a 13-digit DUNS+4 (the +4 is dropped), or a 12-character UEI. Case-insensitive; hyphens and spaces are stripped. An unrecognized shape returns 422.

This endpoint takes no query parameters; any query string returns 400.

Response

Returns the resolved DUNS, the UEI, the entity name, an FFATA evidence count (how many subaward records tie the two identifiers together), and the last-seen date.

Coverage truth

The crosswalk is built from FFATA Section 2 subaward filings since FY2025, where both identifiers co-exist on the same record (tens of thousands of firms indexed). A 404 here means not in the FFATA-derived crosswalk, not not in SAM: the official SAM DUNS-to-UEI translator is admin-gated and not publicly available. For a per-record SAM lookup by UEI, use /api/v1/entities/{uei}.

Errors

• 404: identifier not in the FFATA-derived crosswalk.
• 422: identifier shape invalid (not a 9-digit DUNS, not a 12-character UEI).
• 429: rate limit exceeded (60 per minute per IP).

Example

curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://govconapi.com/api/v1/identifiers/CKV2L9GZKJK3"