My CFDI 4.0 invoice got rejected — the name was off by one letter. Really?
Yes, really. CFDI 4.0 validates the recipient's data against SAT's padrón (registry), and four fields must match exactly: the recipient's RFC, name/razón social, tax regime (régimen fiscal), and fiscal domicile postal code. One wrong accent, one outdated regime code, and the invoice fails at timbrado (certification). This was the single biggest behavioral change from CFDI 3.3 to 4.0.
The four exact-match fields
| Field | Must match | Where to get the truth |
|---|---|---|
| RFC | Character-for-character | Constancia de Situación Fiscal |
| Nombre / razón social | Including accents, no abbreviations | Constancia de Situación Fiscal |
| Régimen fiscal | The code SAT has on file (e.g. 612, 626) | Constancia de Situación Fiscal |
| Domicilio fiscal (CP) | The postal code on record | Constancia de Situación Fiscal |
Legal anchor: CFF Art. 29-A fr IV, plus the Anexo 20/29 filling guides for the régimen field.
How to stop the rejections
- Ask every new client for their Constancia de Situación Fiscal before the first invoice — copy the four fields verbatim, don't trust what they type in an email.
- Re-validate periodically. Clients change regimes (e.g., moving into RESICO) without telling you.
- If it fails at timbrado, fix the field and re-stamp — don't try to "force it through"; the PAC (authorized certification provider) is just enforcing SAT's validation.
One 2026 nuance: SAT has moved against vendors who condition issuing an invoice on the client presenting the constancia — you must ask for the data, but you can't refuse to invoice someone solely for not producing the document on the spot. (The 2026 fine for this is reported but not yet confirmed in primary sources — treat the practice itself as prohibited regardless.)
Frequently asked questions
The client insists the name is right but SAT rejects it. Who's wrong?
SAT's padrón wins, always. Whatever the client believes, the registry is the source of truth — have them check (and update, if needed) their constancia.
Can I just use the generic RFC for everyone?
No. RFC genérico (XAXX010101000 / XEXX010101000) is for the general public and foreign clients respectively — using it for a Mexican client with a real RFC is a red flag.
Does the same strictness apply to the issuer's data?
Yes — your own RFC, name, regime, and CP are validated the same way. Keep your own constancia current too.
Sources
- https://blog.alegra.com/mexico/errores-en-cfdi-mas-comunes/
- CFF Art. 29-A fr IV (recipient data requirements)
- SAT Anexo 20 / Anexo 29 (CFDI 4.0 filling guides) — https://www.sat.gob.mx