RFC Validator

RFC (Mexican tax ID) · Issuer: SAT. CFDI 4.0 e-invoicing, customer onboarding, payroll, Mexican marketplaces.

Format

13 characters for individuals (4 letters + YYMMDD date + 3-char homoclave) or 12 for companies (3 letters).

Check-digit algorithm

1. Validate structure and a real date.
2. Last char is the check: characters map to values (0–9, A=10 … N=23, &=24, O=25 … Z=36, space=37, Ñ=38).
3. Weighted sum with weights 13..2 (companies are left-padded with a space), 11 − (sum mod 11); 11 → 0, 10 → A.

Use cases

CFDI 4.0 e-invoicing, customer onboarding, payroll, Mexican marketplaces.

Code examples

# curl (RapidAPI)
curl -X POST "https://validalatam.p.rapidapi.com/validate" -H "Content-Type: application/json" \
  -H "X-RapidAPI-Key: $RAPIDAPI_KEY" -H "X-RapidAPI-Host: validalatam.p.rapidapi.com" \
  -d '{"type":"MX_RFC","value":"OTZU910208G36"}'

# Python
import requests
r = requests.post("https://validalatam.p.rapidapi.com/validate", json={"type": "MX_RFC", "value": "OTZU910208G36"},
                 headers={"X-RapidAPI-Key": KEY, "X-RapidAPI-Host": "validalatam.p.rapidapi.com"})
print(r.json()["valid"], r.json()["formatted"])

// JavaScript (fetch)
const r = await fetch("https://validalatam.p.rapidapi.com/validate", { method: "POST",
  headers: { "Content-Type": "application/json", "X-RapidAPI-Key": KEY, "X-RapidAPI-Host": "validalatam.p.rapidapi.com" },
  body: JSON.stringify({ type: "MX_RFC", value: "OTZU910208G36" }) });
const { valid, formatted, error } = await r.json();

# Response
{
  "valid": true,
  "type": "MX_RFC",
  "country": "MX",
  "input": "OTZU910208G36",
  "normalized": "OTZU910208G36",
  "formatted": "OTZU910208G36"
}

API plans on RapidAPI

Free plan to get started; paid plans for production volume and batch validation (up to 1000 per request).

See plans on RapidAPI →

FAQ

Other validators