Legal framework in Mexico
Mexico has recognized electronic signatures since the 2003 reform of the Commercial Code (articles 89–114) and the 2012 Advanced Electronic Signature Law. NOM-151-SCFI-2016 governs data-message retention, and the Ministry of Economy oversees certification service providers.
Legal framework
Commercial Code + Advanced Electronic Signature Law
How the legal framework evolved in Mexico
2003
Commercial Code reform (arts. 89–114): electronic signatures gain full validity in commercial matters.
2012
Advanced Electronic Signature Law: regulates the FEA for procedures before the federal public administration.
2016
NOM-151-SCFI-2016: sets the rules for preserving data messages and digitizing documents with evidentiary value.
2024
The Digital Transformation and Telecommunications Agency (ATDT) is created, accelerating the digitization of procedures nationwide.
Types of electronic signature in Mexico
Simple electronic signature (FES)
What you create with Firmiu: your drawn or uploaded signature plus an audit trail (IP, device, date and verification code). Articles 89 and 93 of the Commercial Code recognize it for the vast majority of commercial acts and private contracts.
Advanced electronic signature (FEA)
Uses a certificate issued by an accredited certification service provider and technically guarantees identity and integrity. The law only requires it for specific acts; it is not mandatory for contracts between individuals and companies.
SAT e.firma
The certificate issued by the SAT (tax authority) for tax procedures: filings, CFDI invoicing and dealings with the authority. You do not need it to sign private contracts — it is a tax instrument, not a requirement for agreements between parties.
What makes a signature valid in Mexico?
To carry evidentiary weight a signature must be attributable to the signer and tamper-evident. Firmiu records IP, device, location and a verification code for every signature, producing an audit trail that backs the document before a Mexican court.
Which documents can you sign in Mexico?
Can be signed electronically
- Service and professional-fee agreements
- Residential or commercial lease agreements
- Individual employment contracts and internal HR documents
- Non-disclosure agreements (NDAs)
- Quotes, estimates and purchase orders
- Liability waivers and authorizations
Usually require a notary or handwritten signature
- Wills
- Real-estate sales and mortgages (they require a notarized public deed)
- Notarized powers of attorney
- Civil-status acts, such as marriage or divorce
These lists are indicative: the document type and applicable law determine each case.
How to sign documents in Mexico
Upload your PDF
Upload the document and enter the name and email of the person who must sign.
The signer receives a link
They get an email with a unique link and a verification code.
Signed document
The PDF is signed with its audit trail, ready to download.
Frequently asked questions
- Are electronic signatures legal in Mexico?
- Yes. The Commercial Code and the Advanced Electronic Signature Law have granted them full legal validity for over two decades.
- Are they valid in court?
- Yes. A document signed electronically with a solid audit trail (IP, date, device and verification) is admissible as evidence.
- What documents can I sign?
- Service contracts, leases, employment agreements, quotes and most commercial and civil documents.
- Do I need the SAT e.firma to sign contracts with Firmiu?
- No. The e.firma is a certificate for tax procedures before the SAT. For private contracts — services, leases, NDAs — a simple electronic signature with an audit trail, like the one Firmiu generates, is enough.
- Can I sign a lease agreement electronically in Mexico?
- Yes. Leases don't require a public deed, so they can be executed electronically. The audit trail (IP, date, device and verification) backs who signed and when.
- What is NOM-151 and does it apply to my documents?
- It's the official standard governing the preservation of data messages. It reinforces the evidentiary value of digital documents kept intact; Firmiu records the SHA-256 fingerprint of every signed document, which proves it wasn't altered.
- How is an electronic signature proven in a Mexican court?
- Article 210-A of the Federal Code of Civil Procedure admits information on electronic media as evidence, weighing the reliability of the method. A complete audit trail — date, IP, device and verification — is exactly that evidence.
Official sources
The information on this page is general in nature and does not constitute legal advice. The validity of an electronic signature depends on the applicable legislation and the document type; for specific cases, consult a legal professional.
Guide reviewed and updated: July 2026.
Electronic signatures by profession
Guides for the industries that sign the most documents in Mexico.
Related guides
Are electronic signatures legal? What you need to know
Electronic signatures are legal across Latin America, Spain and the United States. Here's what makes them valid and where they're recognized.
Types of electronic signature: simple, advanced and qualified
Not all electronic signatures are the same. Here are the three levels and which one you need for each document.
What documents can you sign electronically
Electronic signatures work for far more documents than you'd think. Here are the most common ones and the exceptions.
Electronic signature in other countries
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