# CFDI 4.0, fuel, and mileage reimbursement in Mexico: what changed in 2026

> SAT updated the CFDI 4.0 filling guide in 2026. How it affects fuel reimbursement.

**Author:** Rodrigo Vázquez — Mexican Tax Specialist (SAT, CFDI)  
**Published:** 2026-04-27  
**Updated:** 2026-04-27  
**URL:** https://quilometragem.com/blog/cfdi-4-0-fuel-and-mileage-reimbursement-in-mexico-what-changed-in-2026

**TL;DR:** SAT updated CFDI 4.0 for fuel in March 2026; corporate card is the cleanest route to capture deductible VAT.

- Unit code LTR mandatory
- NumeroPedimento above MXN 10,000
- Cash fuel is non-deductible
- Per-km reimbursement needs no CFDI

## What changed in 2026

SAT published an updated *CFDI 4.0 filling guide* in March 2026 with two material changes for fuel reimbursement: the product code 15101514 now requires unit code LTR for liquid fuels, and CFDIs above MXN 10,000 must include the *NumeroPedimento* field or reference to the station ticket. Stations rolled out the change between March and June 2026; CFDIs in the old format are now being rejected by SAT post-emission validation.

## Two reimbursement routes

**Route A**: corporate card pays for fuel; CFDI issued directly to the company. Cleanest option, full ISR and VAT deduction.

**Route B**: employee pays personally, receives a CFDI in their name, requests reimbursement. The company reimburses but **cannot deduct VAT** (CFDI not in the company's name); only the net amount as a documented expense.

Route A is preferable wherever the operation supports it.

## Post-emission validation

SAT escalated post-emission validation in 2026: syntactic validation, catalog checks, cross-reference with the active service-station register, and new 2026 cross-check with station inventory reported under Annex 30 fiscal controls. A CFDI with any inconsistency is flagged invalid and the deducting company gets a *carta invitación*.

## Mileage vs fuel reimbursement

The 2026 change affects fuel reimbursement, not per-km reimbursement. Per-km reimbursement is governed by the trip log and internal policy — no CFDI is needed because the employee is not a provider of goods/services. A common mistake: companies asking employees for a CFDI for the per-km reimbursement. There is none to issue.

## Cash payment trap

ISR Law Art. 27 still requires fuel paid by credit card, debit card, registered check, or transfer to be deductible. **Cash fuel is non-deductible** regardless of CFDI. Operational fix: policy requires card payment with documented emergency exceptions only.

## Checklist for 2026

1. Update the accounting system's CFDI validation module to the March 2026 SAT version.
2. Push corporate cards to drivers.
3. Separate per-km policy from fuel-reimbursement policy.
4. Cross-validate CFDI vs trip log before payment.
5. Retain rejected CFDIs with the SAT reason for 5 years.

## Frequently asked questions

### CFDI in employee name — can the company deduct VAT?

No. To deduct VAT, the CFDI must be issued to the company with the company's RFC.

### Is cash-paid fuel deductible?

No. ISR Law Art. 27 requires card, check, or transfer.

## Sources

- [SAT — Guía de llenado del CFDI 4.0 (versión marzo 2026)](https://www.sat.gob.mx/) — Servicio de Administración Tributaria (2026-04-27)
- [Ley del ISR Art. 27 — Requisitos de las deducciones](https://www.diputados.gob.mx/LeyesBiblio/pdf/LISR.pdf) — Cámara de Diputados (2026-04-27)