Contractor onboarding (W-9)

Collect usable W-9s before the first payout

Name, TIN and signature from Form W-9 for 1099 reporting, checked at upload.

The problem

Unsigned forms, missing TINs and old revisions come back weeks later.
The legal name on the W-9 does not match the payee account.
Year-end 1099 filing reveals TIN errors when they are harder to fix.

With Constaia

Signature, date and SSN or EIN format checked at upload, before the contractor leaves the flow.
Name compared with your payee record; only mismatches go to review.
Constaia checks format, not IRS records: pair it with IRS TIN Matching, available to eligible payers, to confirm the name and TIN combination.

Typical documents

Sample request

curl https://api.constaia.com/v1/analyze \
  -H "Authorization: Bearer $CONSTAIA_API_KEY" \
  -F "file=@document.pdf" \
  -F 'options={
    "expect": "us_w9",
    "checks": {
      "require_signature": true,
      "holder": {
        "full_name": "Jordan Specimen"
      }
    },
    "storage": "none"
  }'

And for the record…

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