​
Introduction

The CFDI (Comprobante Fiscal Digital por Internet) is the standardized electronic invoicing format in Mexico, managed by the country’s tax authority, the SAT (Servicio de Administración Tributaria). This system ensures that all fiscal documents are digitally generated, validated, and reported to SAT in compliance with national tax laws. In this guide we’ll walk you through the steps required to first register a supplier and then issue invoices in their name.

​
Prerequisites

To issue invoices in Mexico via the SAT, you will need:
  • Supplier Information:
    • Name
    • Taxpayer ID (RFC - Registro Federal de Contribuyentes)
    • Address
    • Fiscal regime code (as defined by SAT)
  • Customer Information (same as supplier, plus):
    • CFDI use code (Código de uso CFDI)
  • Line items:
    • Quantity, unit price, and applicable tax rates
    • SAT product/service code (Clave Producto-Servicio)
  • Additional requirements
    • Selected invoice series
    • Place of issue code (Lugar de expedición)
  • Two certificates required by the SAT:
    1. e.firma (FIEL): Confirms your identity before SAT. Required to obtain the CSD below and to authorise the PAC to issue on your behalf as explained in step 3 of the Register a Supplier section below.
    2. CSD (Certificado de Sello Digital): Required to sign electronic invoices and prove they were issued by you.

​
Setup

Configure your Invopop workspace for CFDI invoicing by following these steps in the Invopop Console:
These instructions apply to both the sandbox and live environments, with a few exceptions related to supplier data and registration details when real information is not available.
1

Set up the Supplier Post-Registration Workflow

2

Set up the Supplier Registration Workflow

3

Connect the SAT Mexico App

In the left sidebar, under the Configuration section, click Apps. This will display all available apps.Search for SAT Mexico and click Connect. The app will move to the “Enabled Apps” section.Next, click Configure. This will open a dialog on the right with two fields:
  • Environment: Sandbox / Live
  • Post-registration workflow: SAT supplier post-registration
4

Set up the SAT Issue Invoice Workflow

​
Running

Learn how to register a business entity (supplier) and issue CFDI invoices:

​
Register a Supplier

Registering a business entity requires uploading the CSD to our local provider, SW Sapiens, via a form (see Step 2: Complete Supplier Registration). This upload goes to either the sandbox or live environment, depending on your SAT Mexico App configuration. Each CSD is tied to an RFC. When you submit an e-invoice, including the supplier’s RFC, SW Sapiens checks for a valid CSD linked to it, as SAT requires a valid certificate to issue invoices.
To speed things up, we’ve pre-registered all the test CSDs listed on the SW Sapien test page in the sandbox.If you’re working in sandbox, you can either:
  • Skip this section and go straight to Send an Invoice using a test RFC, or
  • Register your own certificate by following the steps below.
1

Run the Supplier Registration Workflow

In the left sidebar, go to the Contacts section and click Suppliers.Then click +New Supplier and enter the supplier’s data manually using the console, or switch to developer mode (</> icon) to paste the data directly.Here is an example supplier for reference:
SAT Mexico supplier example
{
  "$schema": "https://gobl.org/draft-0/org/party",
  "uuid": "018fbeda-bc61-7000-b66d-398ce3e21c43",
  "name": "ESCUELA KEMPER URGATE",
  "tax_id": {
    "country": "MX",
    "code": "EKU9003173C9"
  },
  "ext": {
    "mx-cfdi-fiscal-regime": "601"
  }
}
Click Build, make sure there are no errors, then click Save.Next, click Select Workflow and execute the Supplier Registration Workflow.
2

Complete Supplier Registration

After it completes, open the Details window and click on Meta. You should see a section called Registration Link with a URL:
Supplier Registration Link
You can access the registration link via the API by fetching the silo entry and locating the meta entry where the key isregistration-link.
Visit that URL to access the form for registering the supplier.
Note that this form can be shared directly with the supplier if required.
Issuer Registration Form
Fill out the form with the following information: Issuer RFC, CSD certificate file (.crt), private key (.key), and the private key password.Follow this guide to generate the CSD certificate and key.When you click Save, the form details are securely sent to the PAC (Proveedor Autorizado de Certificación), who will handle invoice signing and submission to the SAT.
You can fill the form via API by sending a PUT request to the registration link. The payload should be a JSON object with the following fields:
  • csd_file (string): The CSD certificate file (.crt).
  • key_file (string): The private key (.key).
  • password (string): The private key password.
The response will be a JSON object with the following fields:
  • rfc (string): The RFC of the supplier.
  • active_cert (boolean): Whether the certificate is active.
3

Authorize PAC to Issue Invoices

Since we are using a local PAC, you must authorize the PAC to sign, stamp, and send CFDIs to the SAT on your behalf.To do this, visit the following page and sign the manifesto using your e.firma (FIEL).
At this point, you’re ready to start sending invoices on behalf of the supplier.

​
Send an Invoice

The following examples are of partial GOBL documents you can copy and paste directly into the Invopop Console or store via the API as silo entries. GOBL Invoices sent to the SAT require the following properties in order to perform the correct normalization and validation steps. Invopop will try to assign these automatically, but we recommend defining them explicitly before upload:

​
FAQ

Please contact the Invopop support team if you have any questions that are not listed here.