Glossary
CSD
The CSD (Certificado de Sello Digital, digital seal certificate) is the certificate the SAT, Mexico's tax administration, issues linked to the taxpayer's advanced electronic signature, for the specific purpose of sealing the invoices it issues and fully identifying their information.
The SAT explains it on its Certificado de Sello Digital page, accessed October 17, 2026. With it, the taxpayer electronically seals the original string (cadena original) of every invoice it issues, which guarantees the invoice’s origin and uniqueness, and the invoice inherits the properties of advanced electronic signature certificates: integrity, non-repudiation and authenticity. Digital certificates are described in Article 17-G of Mexico’s Federal Tax Code.
The SAT issues it, and the taxpayer generates it through the Genera tu CSD procedure. A taxpayer can use a single seal for its whole operation, head office and branches, or request one for each branch, establishment or location where it issues invoices. The SAT can restrict it temporarily or render it void: if it is restricted and no clarification is filed, the authority voids it within 40 business days at most.
In Odoo 20, the CSD .key file is loaded with its password and the .cer file is linked to that key in the general settings, under certificates and keys, as the Mexican localization guide details.
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