Live Projects / Tool 01

EIN Due-Diligence Checker

Live · v1

Check any US nonprofit's IRS standing in seconds — one plain-English trust card with a green / amber / red verdict. An answer engine, not a database: verdict up front, evidence expandable, every field citing its source and "as of" date.

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Your recent checks are kept on this device only. A cookieless analytics tool counts how the checker is used — never which organizations you look up.

Check a whole portfolio

Vetting a grantee list? Paste up to 50 organization names or EINs — one per line, or a CSV — and get every verdict at once, sorted worst-first so problems surface immediately. Where a name matches several organizations, you pick; it never guesses for you.

Verify by state

Every state has its own page with the same checker plus a live snapshot of that state's nonprofit landscape from the current IRS release — how many organizations are registered there, how many are recognised 501(c)(3)s, how many currently have their exemption revoked, and which categories are largest.

These pages cover federal IRS status. Registering with the IRS and registering to solicit donations in a state are different requirements — state charitable registration still isn't evaluated anywhere on this site.

1,983,563trust cards precomputed — every org in the IRS Business Master File
4.73Mfilings indexed for recency — including 990-N e-Postcards
9trap tests passing on every build
161,185reinstated orgs protected from a false "revoked" flag

What it checks — and what it doesn't

Checked on every org

  • 501(c)(3) status in the IRS Business Master File
  • Tax-deductibility per Publication 78 — including group-ruling subordinates
  • Revocation history, reconciled against reinstatements
  • Filing recency from the 990 e-file index and 990-N e-Postcards

Not evaluated yet

  • Charitable-registration status in the ~41 states that require it
  • 990 financial detail (revenue, spending, compensation)
  • News, litigation, or reputation signals

A diligence tool earns trust by saying "I didn't look" — never by implying "nothing there."

Build log

  1. Build rules, schema, and 98-code reference tables committedJul 2026
  2. IRS Business Master File ingested and verified — 1.98M orgs, church and known-EIN spot checks passingJul 2026
  3. Publication 78 + auto-revocation reconciliation, with trap tests that fail the build before they can mislabel an orgJul 2026
  4. Filing recency — 4.73M filings from the 990 e-file index + 990-N e-PostcardsJul 2026
  5. Name search with match confidence — with a containment gate so a near-miss never auto-resolves wrongJul 2026
  6. Trust-card assembly — 1,983,563 cards precomputed, deterministic rules, 5 card-level checks passingJul 2026
  7. Public checker launched on this pageJul 2026
  8. Workflow features — portfolio batch checking, PDF reports, and status monitoringJul 2026
  9. Automating the monthly IRS data refresh

Colophon — how this is built

Spec first: a full v1 build document with the correctness traps named before any code — group-ruling subordinates that look non-deductible, revoked-then-reinstated orgs that look revoked, churches that look like non-filers. Each trap is a test that fails the build, not the user.

Data comes from IRS.gov directly (Business Master File, Publication 78, the auto-revocation list, the 990 e-file index) — never from a re-publisher's API. Cards are precomputed monthly and served read-only, so there are no third-party calls at request time and no live database to corrupt: the warehouse builds a baked artifact, and the API serves it.

Built with AI in the loop, end to end — the same operating model I bring to organizations: spec → schema → verified 2M-row ingest in a working day, with human judgment on every gate that matters.

PythonPostgres + pg_trgmpolarsFastAPIBaked SQLite artifactGitHub Pages + Fly.io

Checking one is a search box. Checking four hundred is a process.

If your team verifies grantees by hand every cycle — someone working a portfolio against a deadline, re-keying results into a grants system, and re-doing it all next quarter — that is a workflow problem, not a lookup problem. Designing and building that workflow is what I do for foundations and grantmakers.

Tell me what your process looks like now — or if you want the API behind this page, ask for that instead.