KYB API — verify any U.S. business in one call

Q: How do I verify a business by EIN?

Call GET /v1/business?ein=.... See Verify a business by EIN.

KnowFirm is a KYB (Know Your Business) API for developers. Resolve a business across authoritative public sources — IRS (EIN), GLEIF (LEI), SEC (CIK), FDIC, and more — and get back a single canonical entity with strong identifiers, a confidence score, firmographics, and per-field provenance.

What is a KYB API?

KYB ("Know Your Business") is the business equivalent of KYC: confirming a company's identity, registration, and risk signals before onboarding it. A KYB API does this programmatically — you send an identifier or name, and get back verified business data. KnowFirm adds cross-source entity resolution (one business, many sources, merged on shared identifiers) and sanctions/denied-party screening in the same API.

Endpoints

Resolve — GET /v1/business?ein|lei|cik|name
Search — GET /v1/business/search?q=
Screen — POST /v1/screening (U.S. Consolidated Screening List)
Batch enrich — POST /v1/enrich

curl -H "X-API-Key: $KNOWFIRM_KEY" \
  "https://api.knowfirm.com/v1/business?name=bank%20of%20america"

How KnowFirm is different

Self-serve & usage-priced — start on a free tier with no sales call; pay per call as you grow.
Provenance on every field — each value is traceable to its source, with a confidence score.
Sanctions screening included — KYB verification and denied-party screening from one API.
Honest scope — KYB/firmographic data only; not an FCRA consumer-reporting product.

FAQ

How do I verify a business by EIN? Call GET /v1/business?ein=.... See Verify a business by EIN.

Where does the data come from? Public sources — GLEIF (CC0), SEC, IRS, FDIC, DOL Form 5500, and the U.S. Consolidated Screening List. See Data sources & attribution.

Can I use it for credit or hiring decisions? No — KnowFirm is not a consumer reporting agency and the data is not for FCRA-covered eligibility decisions.

Get started: Quickstart.