As of this article's date (November 1, 2026), the SAT (Mexico's tax authority) has not announced a new version of the electronic invoice: CFDI 4.0 (Mexico's electronic invoice) remains in force. The 2027 Economic Package that the Ministry of Finance delivered to Congress on September 8, 2026 does not include a reform to the Federal Fiscal Code. The changes that do matter took effect on January 1, 2026: an invoice that does not cover a real transaction is considered false, the cancellation deadline now sits in the Code itself, and there are more grounds for the SAT to restrict your digital seal. Odoo stamps CFDI 4.0, payment complements, credit notes, Carta Porte 3.1 and foreign trade. Validate your case with your accountant.
What changes in the SAT's electronic invoice for 2027?
For now, nothing officially announced. We found no SAT notice of a new CFDI version or of a new mandatory complement for 2027. The current version is still 4.0.
On the 2027 Economic Package portal, the Ministry of Finance published these revenue initiatives: the Federal Revenue Law, amendments to the Federal Rights Law and amendments to the Income Tax Law. There is no initiative to reform the Federal Fiscal Code, which is where the invoice rules live. On October 27, 2026, the Senate approved the Revenue Law and the amendments to the Federal Rights Law and sent them to the Executive for publication; as of this article's close they had not yet appeared in the Diario Oficial de la Federación (DOF, Mexico's official gazette), which is the text that counts.
One piece is missing: the 2027 Resolución Miscelánea Fiscal (RMF, the annual miscellaneous tax resolution), where the SAT details the operating rules for invoices. As of today it is not published. The current one is the 2026 RMF (DOF, December 28, 2025), with two amending resolutions published in the DOF on July 9 and October 1, 2026. When the 2027 one comes out, review it with your accountant.
What has changed for invoices since 2026?
The reform to the Federal Fiscal Code published in the DOF on November 7, 2025, in force since January 1, 2026, tightened control over invoices. These are the changes that most affect a company that invoices every day:
| Change | What it says | What it means for you |
|---|---|---|
| Real transactions | A new CFDI requirement: it must cover existing transactions, true transactions or real legal acts. If it does not, it is considered false (art. 29-A, section IX) | Every invoice you issue or receive must be backed by the transaction: order, delivery, contract, payment |
| Procedure and penalty | A new procedure for false invoices (art. 49 Bis) that can suspend invoice issuance, and two to nine years in prison for anyone who issues, buys or gives tax effect to false invoices (art. 113 Bis) | Vetting your suppliers is no longer optional: deducting a false invoice has consequences |
| Cancellation deadline | An invoice can be canceled no later than the month in which the annual income tax (ISR) return is filed for the year in which it was issued (art. 29-A) | A year's invoices can be corrected, at the latest, in the month of the annual return |
| Digital seal | New grounds to restrict the Certificado de Sello Digital (digital seal certificate) (art. 17-H Bis), among them: having received invoices the SAT declared false and not correcting your situation within the deadline, or having final tax debts unpaid | If the SAT restricts your seal, you cannot invoice until it is cleared up |
What it costs you: a restricted digital seal halts invoicing, and with it collections, until you clear up the situation.
Until when and how can an invoice be canceled?
Until the month in which the annual ISR return is filed for the year in which the invoice was issued, and provided the customer accepts the cancellation when the law requires it. That is how article 29-A of the Fiscal Code has read since 2026.
The SAT's 2026 cancellation FAQ spells out the rest:
- A reason is always stated: 01 errors with a related invoice (when you replace it with another), 02 errors without a related invoice, 03 the transaction did not take place and 04 named transaction included in a global invoice.
- To correct an invoice, you first issue the new one with the relation "04 Replacement of previous CFDIs" and then cancel the original with reason 01 and the new one's folio.
- The customer has three business days to accept or reject. If they do not respond to the first request, it is canceled; if they rejected the first and do not respond to later ones, it is not canceled until they accept.
- Their acceptance is not needed in several cases, among them: invoices of up to $1,000 pesos, credit notes, transfers, payroll, transactions with the general public, invoices to residents abroad and cancellations within 24 hours after issuance.
Odoo handles this flow from the invoice and asks for the reason on each request. Its documentation makes clear that the request acknowledgment is not conclusive proof that the CFDI was canceled: you must confirm the final status.
What does Odoo need to stamp CFDI 4.0 invoices?
Three things, according to the Odoo 20 Mexican localization documentation: be registered with the SAT with a valid RFC (taxpayer ID), have your Certificado de Sello Digital (CSD, digital seal certificate) and choose a certification provider (PAC). As of November 2026, the documentation lists three compatible PACs: Solución Factible, Quadrum and SW Sapien (Smarter Web). The list may change.
Odoo was built to the SAT's specifications for CFDI version 4.0. The localization is installed in modules: e-invoicing, reports (electronic accounting and DIOT), Carta Porte, and foreign trade and customs entries. Which Odoo edition you need for each one is explained in Odoo Community vs Enterprise.
Which tax documents does Odoo generate in Mexico?
Those of daily operations, with limits worth knowing before you implement:
| Document | What Odoo does | Limit or detail |
|---|---|---|
| Invoice (type I, income) | Stamps CFDI 4.0, with or without addenda | Requires RFC, CSD and PAC configured |
| Credit note (type E, egreso: a credit note) | Links it to the original invoice by its fiscal folio, as the SAT requires | Without the link, it does not comply |
| Payment complement | Generates it from the recorded payment and sends it to be stamped | Only for PPD invoices |
| Global invoice | Groups sales to the general public into a single invoice | If a customer later asks for their invoice, the global one is canceled with reason 04 and reissued |
| Carta Porte 3.1 | Generates the shipping waybill from the inventory delivery | Does not support income-type Carta Porte or air, rail or maritime transport |
| Foreign trade 2.0 | Adds the complement to export invoices | Mandatory since 2018 for type A1 exports |
| Customs entries | Links the customs entry number to imported product lines | Once entered, the number cannot be edited or repeated |
| Electronic accounting and DIOT | Generates chart of accounts, trial balance and journal entries in XML, and the DIOT in TXT | Each supplier needs its transaction type entered |
On the Carta Porte: the SAT establishes that since July 17, 2024 only CFDI 4.0 issuance with version 3.1 of the complement is valid, mandatory for anyone transporting goods within the national territory. If your company delivers with its own fleet, this is configured together with the warehouse; we cover it in inventory and warehouse in Odoo for distributors.
When is the payment complement issued?
When you collect an invoice issued as PPD (installment or deferred payment), no later than the fifth calendar day of the month following the payment, per the Miscellaneous Tax Resolution rule on CFDIs for payments received. You can issue one per payment or one for all of a customer's payments in the month.
In Odoo, the payment method is assigned automatically according to the due date: if the expected payment date falls within the month, the invoice comes out as PUE (single payment); if it falls outside, as PPD. The complement is only generated for PPD invoices. That is why each customer's credit terms must be entered correctly.
What it costs you: customers who chase you for missing complements and collections that do not match your PPD invoices.
What to review in your invoicing before 2027?
- Validity of your CSD. Without a valid digital seal you cannot stamp.
- Invoices your suppliers issue to you. Each one should have behind it an order, a warehouse receipt or a contract that proves the transaction.
- Pending cancellations for the year. Any you must make for 2026, do them before the annual return deadline closes.
- Payment complements. Each collection on a PPD invoice should have its complement before the 5th of the following month.
- The 2027 RMF. When it is published, ask your accountant for a summary of what changes for your company.
If you already use Odoo and invoicing is giving you trouble (complements that do not go out, stuck cancellations, badly configured tax data), look at Odoo rescue.
Glossary
- CFDI
- Comprobante Fiscal Digital por Internet (digital tax receipt over the internet): the electronic invoice validated by the SAT.
- CSD
- Certificado de Sello Digital (digital seal certificate): the file your system uses to sign each invoice. It is issued by the SAT.
- PAC
- Certification provider authorized by the SAT that stamps (validates and seals) your invoices.
- PUE and PPD
- Single-payment and installment or deferred payment. PPD invoices require a payment complement when collected.
- RMF
- Resolución Miscelánea Fiscal (Miscellaneous Tax Resolution): annual SAT rules detailing how to comply with tax laws, including invoicing.
Frequently asked questions
Will there be a CFDI 5.0 in 2027?
As of this article's date (November 1, 2026) the SAT has not announced a new version. The current one is 4.0.
Does the 2027 Economic Package change the invoice rules?
The Ministry of Finance did not include a reform to the Federal Fiscal Code in the package. It did propose amendments to the Income Tax Law; check with your accountant whether any affect you.
Does Odoo stamp directly with the SAT?
No. Odoo sends the invoice to a PAC, which stamps it. The documentation lists the compatible PACs; you need to contract one.
Does this article replace my accountant's opinion?
No. It explains the published rules and how Odoo handles them. Each company has its own tax regime and particulars: validate your case with your accountant.
Sources: Expansión, «Senado aprueba Ley de Ingresos y Ley Federal de Derechos 2027», 27 de octubre de 2026 · Secretaría de Hacienda, «Paquete Económico para el Ejercicio Fiscal 2027», septiembre de 2026 · Uno TV, «Hacienda entrega a diputados Paquete Económico 2027», 8 de septiembre de 2026 · DOF, «Decreto por el que se reforman, adicionan y derogan diversas disposiciones del Código Fiscal de la Federación», 7 de noviembre de 2025 · Código Fiscal de la Federación, texto vigente (última reforma DOF 09-04-2026) · DOF, «Resolución Miscelánea Fiscal para 2026», 28 de diciembre de 2025 · DOF, «Primera Resolución de Modificaciones a la RMF 2026», 9 de julio de 2026 · DOF, «Segunda Resolución de Modificaciones a la RMF 2026 y Anexo 2», 1 de octubre de 2026 · SAT, «Preguntas frecuentes y escenarios de cancelación 2026», agosto de 2026 · SAT, «Complemento Carta Porte» · SAT, regla de la RMF «Expedición de CFDI por pagos realizados» · Odoo, «Mexico», localización fiscal, documentación de Odoo 20.0, accessed November 2026
