How to obtain the SAT e.firma for the PUI
The e.firma is the SAT’s advanced electronic signature and one of the prerequisites to interconnect with the Single Identity Platform. Here we explain what it is, exactly what it’s for in the PUI, the difference between an individual and a company, and the general requirements to obtain it from the SAT. Honestly: the official procedure is done by the SAT; we guide you through it.
What the e.firma is and why the PUI requires it
The e.firma (formerly FIEL) is the advanced electronic signature issued by the SAT. It is equivalent to your handwritten signature with legal validity: it unambiguously identifies whoever signs digital documents and procedures. It consists of a certificate and a private key, and it is obtained from the Tax Administration Service.
In the context of the PUI, the e.firma is the mechanism by which your establishment identifies itself with legal validity to the platform when requesting interconnection. It is not that the PUI is a fiscal procedure; it simply reuses the SAT’s e.firma as solid proof of identity, because it is already the country’s legal signature standard.
So even though full interconnection today awaits the SNIP Operations Manual, having a valid e.firma is something worth resolving now. It is a prerequisite that depends only on you and the SAT, not on the pending manual.
The essentials about the e.firma
Four ideas to understand it without jargon.
The SAT issues it
It is an official procedure with the Tax Administration Service. No third party sells it and you don’t "buy" it online.
It has legal validity
It is equivalent to your handwritten signature. That is why it serves as solid proof of identity for PUI interconnection.
It belongs to a person or the company
Individual: the holder’s. Company: the legal representative’s. It is not a generic hotel signature.
It must be kept valid
It has an expiry date. Review and renew it in time so you are not left without a signature when you need it.
How it is obtained, in general terms
The official procedure and its exact requirements are defined by the SAT. This is the general route so you know what to expect.
- Identify who will signIf your lodging is an individual, the e.firma will be the holder’s. If it is a company, the legal representative’s. That determines which documents are requested.
- Gather your ID and tax detailsIn general the SAT requests valid official ID, CURP and proof of your tax details. For a company, the company’s and the legal representative’s documentation is added.
- Book and attend the SAT appointmentThe e.firma is normally obtained in person because it includes biometric data capture. You book an appointment and go to a SAT office.
- Receive your certificate and safeguard itOn completion, you obtain your e.firma files and a password. Keep them carefully: they are sensitive, are not shared and must not be logged in any system.
Individual vs. company
Your legal form changes whose e.firma it is and which file you use. Here is the key difference.
Individual
You use your personal e.firma and RFC. It is you, as the lodging’s holder, who signs and identifies the establishment.
Company
You use the company’s e.firma and RFC, exercised by the legal representative. The identity is the company’s, not just any employee’s.
Different documentation
A company additionally provides the articles of incorporation and the legal representative’s power of attorney. An individual, their ID and personal details.
Relationship with LlaveMX
An individual uses their individual file in LlaveMX; a company, the company file. The e.firma aligns with that same legal form.
Same final goal
In both cases the e.firma serves the same purpose: to identify you with legal validity to the platform so you can interconnect.
Same security care
Whether individual or company, the e.firma files are sensitive: they are safeguarded, not shared and never exposed in logs or messages.