Plain Dot | API · Docs

    API reference

    Core endpoints for TIN matching, 1099 filing, W-9 collection, and verifications.

    POST
    /v1/tin/match
    Real-time IRS TIN match for a single recipient.
    Request
    {
  "name": "Acme Corp",
  "tin":  "12-3456789"
}
    Response
    {
  "id":     "tin_01HX...",
  "result": "match",
  "checked_at": "2026-05-28T19:04:11Z"
}
    POST
    /v1/filings/1099
    Create a 1099 filing (NEC, MISC, K, INT, DIV).
    Request
    {
  "form": "1099-NEC",
  "payer_id": "pay_01HX...",
  "recipients": [{"id":"rec_01...","amount":2400.00}]
}
    Response
    {
  "id":     "fil_01HX...",
  "status": "queued",
  "irs_submission_id": null
}
    POST
    /v1/w9/request
    Send a W-9 request to a recipient by email.
    Request
    {
  "recipient_email": "vendor@northwind.com",
  "expires_in_days": 14
}
    Response
    {
  "id": "w9_01HX...",
  "url": "https://w9.plaindot.com/abc123",
  "status": "sent"
}
    GET
    /v1/verifications/:id
    Retrieve a Check verification result.
    Request
    // path params only
    Response
    {
  "id":     "chk_01HX...",
  "type":   "i9",
  "status": "verified"
}