Definition
CFDI stamping (timbrado) is the process by which a PAC authorizes and digitally seals a tax voucher with the SAT, assigning the UUID and seal that make the CFDI valid. In freight it includes the CFDI (income or transfer) and, when applicable, the Carta Porte 3.1 complement. OCL Cargo can stamp; it verifies on the buyer side.
Asking the buyer TMS to 'stamp the carrier's freight' is a role error.
First validate the XML; then the PAC stamps; then the buyer audits.
What CFDI stamping means in practice
CFDI stamping (timbrado) is the process by which a PAC authorizes and digitally seals a tax voucher with the SAT, assigning the UUID and seal that make the CFDI valid. In freight it includes the CFDI (income or transfer) and, when applicable, the Carta Porte 3.1 complement. OCL Cargo can stamp; it verifies on the buyer side.
Validating data before sending to the PAC avoids costly rejection loops.
Typical mistakes in Mexico
1.Confusing stamping with payment approval
Being stamped does not mean rate or POD match.
2.Believing OCL or another auditor 'stamps' for the carrier
Issuance and the seal stay with the issuer's PAC.
How to measure or govern it in the TMS
Track stamping rejections by cause (catalog, figures, locations).
On the buyer side: % received XMLs with valid UUID indexed to the trip.
Select a step to see detail
Step detail · 01
Define the object
Step 1
Link to OTIF, cost, and compliance
Direct tax compliance; rejection cost hits the issuer and delays AP.
OTIF does not depend on stamping, but the trip's financial close does.
Sources and further reading
- Glossary: PAC CFDI.
- Guide: how to create Carta Porte 3.1.
- Frame: transport invoicing 2026.
Key takeaways5 points
- CFDI stamping = tax certification/seal the PAC applies to the voucher.
- Without valid stamping the CFDI has no tax effect.
- Done by the issuer (carrier) via its PAC, not the shipper.
- OCL can stamp: it verifies the already-stamped CFDI before payment.
- Carta Porte 3.1 catalog errors are a common rejection cause.
Does your RFP confuse stamping with auditing?
Frequently asked questions
It is the certification and digital seal a PAC applies to the CFDI with the SAT, assigning UUID and tax validity. In freight it may include Carta Porte 3.1.
Yes. OCL can stamp invoices and Carta Porte; it also verifies the file in buyer-side audit.
Without stamping there is no valid CFDI to audit; with stamping you still must match rate, GPS, and POD.
No. The issuer integrates its PAC; the buyer integrates verification into the trip file.