tax_residence_certificate

Tax residence certificate

Tax residence certificate from any country for double tax treaty purposes (including IRS Form 6166).

Category: Tax
Country: International
Extracted fields: 8 fields
Cost: 1 credit

tax_residence_certificatespecimen

Holder name
Holder ID number
Issue date
Country
Tax year
Treaty
Issuing authority
Verification code

What it checks

Holder. Name, number or date of birth match what you expect.
Recency. Issued less than N days ago.

Extracted fields

Holder nameholder_name
Holder ID numberholder_id
Issue dateissue_date
Countrycountry
Tax yeartax_year
Treatytreaty
Issuing authorityissuing_authority
Verification codeverification_code

Sample request

curl https://api.constaia.com/v1/analyze \
  -H "Authorization: Bearer $CONSTAIA_API_KEY" \
  -F "file=@document.pdf" \
  -F 'options={
    "expect": "tax_residence_certificate",
    "checks": {
      "max_age_days": 90,
      "holder": {
        "full_name": "Carmen Especimen Ruiz"
      }
    },
    "storage": "none"
  }'

Sample response

Fictitious data. Shortened response.

200 OK · application/json

{
  "id": "an_01J9Z3K8QW4T6Y2B7N5M1R0PXC",
  "object": "analysis",
  "status": "completed",
  "livemode": false,
  "document": {
    "type": "tax_residence_certificate",
    "label": "Tax residence certificate",
    "confidence": 0.97
  },
  "verdict": {
    "expected": [
      "tax_residence_certificate"
    ],
    "match": true,
    "status": "valid",
    "reasons": [
      {
        "code": "type_match",
        "severity": "info",
        "message": "The document is: Tax residence certificate."
      }
    ]
  },
  "fields": {
    "holder_name": {
      "value": "ESPECIMEN",
      "confidence": 0.99,
      "validated": true
    },
    "holder_id": {
      "value": "ESPECIMEN",
      "confidence": 0.98,
      "validated": null
    },
    "issue_date": {
      "value": "2026-09-01",
      "confidence": 0.97,
      "validated": null
    },
    "country": {
      "value": "ESPECIMEN",
      "confidence": 0.96,
      "validated": null
    },
    "tax_year": {
      "value": 1,
      "confidence": 0.99,
      "validated": null
    },
    "treaty": {
      "value": "ESPECIMEN",
      "confidence": 0.98,
      "validated": null
    },
    "issuing_authority": {
      "value": "ESPECIMEN",
      "confidence": 0.97,
      "validated": null
    },
    "verification_code": {
      "value": "ESPECIMEN",
      "confidence": 0.96,
      "validated": null
    }
  },
  "checks": [],
  "warnings": [],
  "storage": {
    "mode": "none",
    "file_deleted_at": "2026-09-29T10:00:02Z",
    "expires_at": null
  },
  "usage": {
    "credits": 1,
    "pages": 1
  }
}

FAQ

Does Constaia prove the document is authentic?

No. It checks the type, data consistency and your rules, and flags signals such as a possible edit or a screen photo. That does not prove authenticity.

Is a copy of the document kept?

No, unless you ask for it. With storage "none" (the default) the file is deleted when the analysis ends.

And for the record…

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