Validator

Credits

With no credits, the four paid ones respond HTTP 400 with code 601 and a message that says (VALIDATOR-MODULE).

A CFDI's status with the SAT

Queries the SAT service with the same data as the CFDI's QR code. It tells you whether it's active or cancelled, whether it can be cancelled and where its cancellation stands.

curl -sS -G "$FD_API/validator/cfdi" \
  -H "X-Api-Key: $FD_API_KEY" \
  --data-urlencode "uuid=6FA90F39-2D7A-4F1C-9B3E-5C1D8A0E7B42" \
  --data-urlencode "rfcemisor=EKU9003173C9" \
  --data-urlencode "rfcreceptor=XIA190128J61" \
  --data-urlencode "total=2494.58"

{
  "message": "La consulta se realizó exitosamente en el SAT",
  "code": "200",
  "sat_response": {
    "codigoestatus": "S - Comprobante obtenido satisfactoriamente.",
    "escancelable": "Cancelable con aceptación",
    "estado": "Cancelado",
    "estatuscancelacion": "Plazo vencido",
    "validacionefos": "200",
    "fecha_consulta": "2026-11-03 10:15:42",
    "fecha_cancelacion": null,
    "fecha_solicitud_cancelacion": "2026-10-28 09:34:50"
  }
}

Where the cancellation dates come from

The SAT status service returns no dates. Both come from the acknowledgment the SAT issued when the key's account cancelled the CFDI through the platform, and they're in central Mexico time.

A recipient's tax data

Tests whether an RFC, its name, postal code and regime match the SAT before you invoice. To find out, it stamps a test CFDI with that data in a separate test environment: it uses neither your folios nor your CSD. The data goes in headers, with these exact names.

curl -sS "$FD_API/validator/fiscalinfo" \
  -H "X-Api-Key: $FD_API_KEY" \
  -H "Rfc: XIA190128J61" \
  -H "Nombre: XENON INDUSTRIAL ARTICLES" \
  -H "Codigopostal: 76343" \
  -H "Regimen: 601"

{
  "old_balance": 46,
  "new_balance": 45,
  "code": 200,
  "short": "OK",
  "message": "The fiscal information provided is correct.",
  "query_date": "2026-11-03 10:15:42"
}

{
  "old_balance": 45,
  "new_balance": 45,
  "type": "RequestException",
  "short": "Wrong Data",
  "sat_code": "CFDI40145",
  "message": "CFDI40145 - El campo Nombre del receptor, debe pertenecer al nombre asociado al RFC registrado en el campo Rfc del Receptor.",
  "code": 400
}

When something doesn't match, short is Wrong Data and sat_code carries the SAT key (CFDI40143, CFDI40145, CFDI40147…), the same one you'd see when stamping. It's in the error matrix.

• It can take up to 60 seconds: set that timeout in your client.
• It only uses a credit when the data passes. A Wrong Data is free.
• Call it from your server: the Rfc, Nombre, Codigopostal and Regimen headers aren't allowed from a browser.

RFC structure

Checks that the rfc parameter has an RFC's structure (letters, a real date and the homoclave) and tells you whether it's generic, foreign, a company (12 characters) or an individual (13). It doesn't query the SAT: it doesn't confirm the RFC is registered. Use fiscalinfo for that, or let the SAT validate it when stamping.

{
  "code": 200,
  "data": {
    "contribuyenteRFC": "XIA190128J61",
    "sncf": false,
    "subcontratacion": false,
    "generico": false,
    "extranjero": false,
    "moral": true,
    "fisica": false
  },
  "query_date": "2026-11-03 10:15:42"
}

sncf and subcontratacion are kept for compatibility and are always false. This endpoint returns its errors with code as text: "400" for a malformed RFC and "401" for everything else (key, missing parameter or no credits).

Certificate in the LCO

Looks up a digital seal certificate in the LCO, the certificate list the SAT publishes. Send the certificate number's 20 digits in nocertificado. data carries what the list publishes for that certificate; for example:

{
  "code": 200,
  "data": {
    "noCertificado": "30001000000500003416",
    "rfc": "EKU9003173C9",
    "validezObligaciones": "1",
    "estatusCertificado": "A",
    "fechaInicio": "2023-05-18T11:43:51",
    "fechaFinal": "2027-05-18T11:43:51"
  },
  "query_date": "2026-11-03 10:15:42"
}

This query depends on an external service and has no timeout of its own: set one in your client.

SAT 69-B list

Looks up the rfc parameter in the article 69-B list of the CFF (taxpayers issuing vouchers for simulated transactions). If it's not there, it responds codestr: "whitelisted" and data: null. If it is, it responds codestr: "blacklisted" with the list row in data.

{
  "code": "201",
  "codestr": "blacklisted",
  "message": "WARNING! This RFC is BLACKLISTED",
  "data": {
    "rfc": "AAA010101AAA",
    "contribuyente": "EMPRESA DE EJEMPLO SA DE CV",
    "situacion": "Desvirtuado",
    "estado": "desvirtuado",
    "pub_sat_presuntos": "01/01/2025",
    "pub_sat_desvirtuados": "01/06/2025",
    "actualizado_en": "2026-11-03 03:15:00"
  },
  "query_date": "2026-11-03 10:15:42"
}

Validator balance

Responds { "code": 200, "balance": 354, "query_date": "…" }. That's the validator credit balance; your stamping folios are in GET /account/balance.