CFDI Validation API
Integrate tax validation into your systems. REST API with bilingual JSON responses.
Base URL: https://herramientasfiscales.mx
Anonymous
10 req / day
No registration
With API Key
100 req / day
Free, request below
Endpoints
Response fields
validboolean — true if no errors
cfdiInfoIssuer, receiver, total, date data
issues[].severity"error" | "warning" | "info"
issues[].codeSAT code (CRP20265) or custom (EQUIV_DR_INCORRECT)
issues[].messageBilingual explanation in natural language
issues[].howToFixConcrete fix steps
issues[].autoFixabletrue if auto-fixable
issues[].isRootCausetrue if root cause of other errors
Rate limit headers
http
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 99
X-RateLimit-Reset: 2026-03-30T23:59:59Z
X-Tier: freeHTTP codes
200Validation successful (check valid field)400Invalid request (empty XML, wrong format)401Invalid or inactive API key413File too large (max 10MB)429Rate limit exceededRequest API Key
Free. You'll receive your key within 24 hours.