> ## Documentation Index
> Fetch the complete documentation index at: https://docs.taxrock.com/llms.txt
> Use this file to discover all available pages before exploring further.

# July 16, 2026

> TIN verification: verify a TIN + name against IRS records

You can now verify a TIN + name pair against IRS records.

* **New endpoint: [Verify a TIN](/api-reference/tin-match/verify)** (`POST /tin-match/verify`).
  Send a TIN with a business name, or an individual first and last name. SSNs and EINs
  both verify. A `200` carries one of three results: `Matched`, `Mismatched`, or
  `NotIssued`. See [TIN verification results](/api-reference/tin-match-results) for how
  to read every response.
* **New scope: `verify:tins`.** Existing connections keep working unchanged; to use TIN
  verification, add `verify:tins` to your authorize request and have the user re-consent
  once. See [Authentication Details](/authentication-details#scopes). The
  [Quickstart](/quickstart)'s authorize-URL builder has a checkbox for it.
* **Deferrals.** Rate limits for this feature are generous, but if they are ever
  exceeded, you will get a `503 verification_deferred` with a `Retry-After` header.
  The header is a worst-case estimate; a retry may succeed much sooner.
* **Usage.** Every delivered result counts toward the organization's monthly
  TIN-verification usage, billed to the TaxRock organization the delegating user
  belongs to.
* **Sandbox demo data.** On the sandbox server, results are deterministic by the TIN's
  last four digits, so every response path can be exercised. See the
  [Sandbox testing table](/api-reference/tin-match-results#sandbox-testing).
* **Clearer malformed-request errors** on all endpoints: an unparseable or empty request
  body now returns `400 invalid_request` with "Request body is invalid or malformed
  JSON."