What is a CSD and Why is it Important?

A CSD is a set of digital files issued by Mexico’s SAT (Tax Administration Service) that identify a taxpayer electronically and allow them to securely sign digital tax documents. The purpose of the CSD is to provide certainty that a document has been issued by the rightful taxpayer and has not been tampered with.

The CSD consists of two main components:

1. The .CER file: This is the digital certificate that contains the taxpayer’s public key. It acts as a “public-facing identity.”

2. The .KEY file: This is the private key, which must be kept confidential. It is used to create the digital signature and ensure that only the taxpayer can sign documents.

These two files work together to generate a digital seal, which guarantees the integrity of the document.

What is the CSD used for?

A CSD is primarily used to generate and digitally sign CFDIs (Digital Tax Receipts), which are mandatory for all tax-compliant businesses and individuals in Mexico. The SAT requires all CFDIs to be validated with a digital seal created using the CSD. This ensures that:

• The invoice or document was created by the authorized taxpayer.

• The document has not been altered after it was issued.

The CSD is essential not only for invoicing but also for issuing payroll receipts, credit notes, and any other type of CFDI required under Mexican tax law.

How to obtain a CSD?

To obtain a CSD, you need to:

1. Generate a private key and a corresponding request file (.REQ) using SAT’s software.

2. Submit the request in person at the SAT office or through its online portal, along with your electronic signature (e.firma).

3. Download the issued CSD files (.CER and .KEY) after the SAT has processed your request.

CSDs and APIs for Electronic Invoicing

In addition to understanding the basics of the CSD, businesses that issue CFDIs frequently can benefit from using an API for electronic invoicing, such as Facturapi.

When using an API, the CSD is integrated into the platform, allowing the API to handle the generation and stamping of CFDIs automatically. This simplifies compliance and saves time for businesses by automating:

• The validation of invoices with SAT.

• The application of digital seals.

• The management of issued invoices.

With tools like Facturapi, businesses can streamline their invoicing process while ensuring full compliance with SAT’s requirements.

The CSD is an indispensable tool for any taxpayer or business in Mexico that needs to comply with electronic invoicing regulations. By securing your CSD and integrating it into solutions like an API, you can ensure the authenticity and integrity of your digital tax documents while simplifying your invoicing processes.

If you’re looking for a simplified and efficient solution, consider exploring an invoicing API like Facturapi to handle all your electronic invoicing needs seamlessly.