Frequently asked questions

How do I create a IdCCP UUID for Carta Porte v3.0?

The XML specification is [C]{3}[a-f0-9A-F]{5}-[a-f0-9A-F]{4}-[a-f0-9A-F]{4}-[a-f0-9A-F]{4}-[a-f0-9A-F]{12}

Use FirmaSAT UUID and replace the first three characters with "CCC" (capital C three times)

Example:
1. FirmaSAT UUID
918ddd32-3184-4806-ae76-541cf7f05e34
2. edit -->
CCCddd32-3184-4806-ae76-541cf7f05e34
3. In XML:
IdCCP="CCCddd32-3184-4806-ae76-541cf7f05e34"

Why do strange characters like Ã© appear in my output?

All output (except help and error messages) is in UTF-8. On the command-line console or in an old text editor that is not UTF-8-aware, the accented characters (áéíóúñ) will appear as two "funny" characters. For example, "México" will appear as "MÃ©xico". To fix, change the console font and code page, or output to a text file and use a text editor that can cope with UTF-8.

Why do I get an error code -28 XML_FACET_ERROR?

If you get an error of the form "Value is not in the enumeration for type" similar to this:

Error code -28: XML restriction is violated/XML restriccion es violada (XML_FACET_ERROR):
Bad attribute/atributo mal [cce11:Mercancia/@FraccionArancelaria] (line 41):
  Value '03044402' is not in the enumeration for type
  'catComExt:c_FraccionArancelaria'/El valor no esta en la enumeracion para el tipo

it means you need to upgrade to the latest version of FirmaSAT. SAT is continually updating their catalog files with extra values in the enumerations. Detecting these changes requires an upgrade to the latest FirmaSAT.

How can I check that the password for my key file is valid?

See Checking the key password with FirmaSAT.

How do you create a Cancelación?

We know of three different ways that a PAC might ask for a cancellation:

Submit a PFX file, which contains your encrypted private key, along with your password! You can create this (at your own risk) with FirmaSAT. See Make a PFX file.
Insert a 'llaveCertificado' element in a 'Cancelacion' XML document (which is your unencrypted private key!). You can use the GETKEYSTRING command in FirmaSAT to create this (at your own risk). See Get Private Key as a String.
Create a digitally-signed XML-DSIG Cancelacion document. You can do this with the CryptoSys PKI Toolkit and SC14N.
See How to create a SAT Cancelacion document using CryptoSys PKI Pro and SC14N
2022-02-02: Re-written for 2022 CFDI versión 4.0.

Why is this in English? Why is your Spanish so bad?

Sorry, we're Australian and not Spanish speakers. We have tried our best with what knowledge we have and the help of our trusty assistant, Miss Google Translate. Please provide us with feedback if you think our Spanish is wrong. And, yes, the Monty Python quote in the Help was a deliberate joke (see Monty Python - Dirty Hungarian Phrasebook).

To contact us or comment on this page, please send us a message.

This page last updated 28 November 2023

Frequently asked questions

Contact us