RFC validation

The RFC (Registro Federal de Contribuyentes) is Mexico's tax ID, issued by SAT. It has a strict 18-character structure that encodes the taxpayer type, a date, and a verification digit. This endpoint validates that structure locally — no external calls, no credentials, sub-millisecond response.

Validate an RFC

POST /v1/rfc/validate

{ "rfc": "COSC8001137NA" }

The rfc field accepts 12-character (moral) or 13-character (física) RFCs, case-insensitive.

Response (200 OK):

{
  "rfc":        "COSC8001137NA",
  "valid":      true,
  "type":       "fisica",
  "is_generic": false,
  "is_foreign": false
}

Field reference

Field	Type	Description
`rfc`	string	The RFC in uppercase, as stored by SAT
`valid`	bool	Always `true` on 200 — invalid RFCs return 422
`type`	string	See type table below
`is_generic`	bool	`true` if RFC is the generic billing placeholder (`XAXX010101000`)
`is_foreign`	bool	`true` if RFC is the foreign party placeholder (`XEXX010101000`)

RFC types

`type`	Length	Who holds it
`fisica`	13	Natural person (persona física)
`moral`	12	Legal entity / company (persona moral)
`generic`	13	SAT placeholder for counter sales (`XAXX010101000`)
`foreign`	13	SAT placeholder for foreign parties (`XEXX010101000`)

What "valid" means

The validation checks:

Format: correct character classes per position ([A-ZÑ&]{3,4} + YYMMDD + homoclave + check digit)
Date: the embedded YYMMDD is a real calendar date (rejects e.g. month 13 or February 30)
Check digit: the last character matches the computed verification digit

Responses

Status	What happened	What to do
`200`	RFC is structurally valid	Use the `type` and flags
`422`	RFC failed format, date, or check-digit validation	Ask the user to re-enter their RFC

Example 422 error:

{ "errors": { "rfc": ["The rfc is not a valid Mexican RFC."] } }

RFC validation is synchronous and local — it never calls SAT or any external service. Use it as a fast first gate before any operation that requires a valid RFC.