Many companies in Mexico use electronic signature thinking they are protected. And technically they are right: they digitally signed. The problem is that not all electronic signatures have equal value when there's a dispute. NOM-151 He or she can decide whether a contract will be held or fall before a judge.
Important clarification:
The Digital Signature with Validity NOM-151 that we describe in this article isn't the .sign of SAT.The .sign (formerly called FIEL) is a certificate that issues the SAT only for tax proceedings and statements to the government. NOM-151 It's for private contracts between businesses and people: leases, credit, insurance, digital onboarding, and so on.
What's a simple electronic signature?
The simple signature is any electronic action that a person does to express his or her agreement with something.
- A click on a "I accept" button
- A sign image drawn on screen or scanned
- A code sent by SMS (OTP) that the user enters
- Write the name at the end of an email
It's easy to implement and doesn't require specialized technology. But it's got a serious problem: if someone challenges the contract, the company can't easily prove who signed, when they did and that the document was later unchanged.
What's a Validity Digital Signature NOM-151?
The Digital Signature with Validity NOM-151 goes far beyond a click or an image. When someone signs a document with this level, several things occur at once:
- A document fingerprint is generated - any after-file changes, as a minimum as they are, are automatically detectable.
- A certified body registers the exact date and time of signature - That's called a time seal. NOM-151 and has full legal validity in Mexico.
- The name of the signatory to the document — the signature is not merely accepted; it is verified who the signer is.
- A complete and auditable file is generated - with all evidence of the process, available if one day you have to come to a trial.
In simple terms:
with the signature NOM-151If anyone tries to say "I have never signed that" or "that document was altered," the company has solid evidence to prove that otherwise. with a simple sign, that evidence simply doesn't exist.
Maximum level: Digital Signature NOM-151 + Biometric with NOM-151
There's a third level that adds an identity check by face recognition. Before signing, the system confirms that the person's who they say they are: looks at their face in real time and detects that they're a real person, and they're not a photo or photo.
That's especially useful if I'm a person that the company doesn't have prior knowledge about - for example, with an account's digital opening, credit or onboarding of new customers.
- Monitoring of INE or sign's passport
- Facial recognition with life detection (confirms that she's a real person)
- Stamp of time NOM-151 certificate
- Digital file with video, photo and complete process registration
Comparative: What does each guy offer?
Simple Signature
Click / image / OTP
NOM-151 Digital Signature
Certificated with time stamp
Biometric + NOM-151
Reported and certified
Prove who signed?
No
Prove who signed?
Partial
Prove who signed?
Yes - with biometrics and INE
Do you detect subsequent changes?
No
Do you detect subsequent changes?
Yes
Do you detect subsequent changes?
Yes
Stamp of time NOM-151
No
Stamp of time NOM-151
Yes - attested
Stamp of time NOM-151
Yes - attested
Value before a judge
Low - easily refutable
Value before a judge
High - certified evidence
Value before a judge
Maximum - complete file
Ideal for
Internal use low risk
Ideal for
Commercial contracts, leases
Ideal for
Finance, credit, digital onboarding
When to use every guy?
Simple signature - when applicable
- Internal approvals between employees of the same company
- Low-risk documents between parties with established relation
- Processes where a dispute is highly unlikely or with minimum consequences
Digital Signature with Validity NOM-151 - for contracts to be held
- Residential or commercial lease contracts
- Trade agreements with third parties
- Service contracts with criminalization clauses
- Any document where the exact date of signature matters
Digital Signature NOM-151 + Biometric with NOM-151 - necessary in regulated sectors
- Retirement and electronic customer onboarding
- Consumer and corporate credit contracts
- Institutions regulated by CNBV (banks, sofums, financial)
- Any procedure with an obligation to check the signature's identity
What can happen if you choose wrong
A financial sector company uses simple sign for credit contracts. A client stops paying. When the company tries to collect, the debtor says that they never signed that contract.
The company cannot prove who signed. It cannot prove that the document was unchanged. It has no certified record of how soon the signature happened. The judge, with his lack of evidence, challenges his debtor.
with a Validity Digital Signature NOM-151That same scenario completely changes. The company has a certified time stamp, evidence of the signing process and a file that can be submitted directly to the judge. To successfully challenge that contract becomes practically impossible.
The actual cost of postponing this change:
Implement Signature NOM-151 It costs a fraction of what can cost a single lost dispute. Most of the companies that change do so after they lose their first case - when it was already too late.
How to start without complications?
With JAAK you don't need a technical integration or to hire a development team to get started. You have two paths:
- Self-service: Enter the web platform today, upload your document, indicate who should sign and get ready. In minutes you have a registered signature with NOM-151 No code, no contracts, no complications.
- Integration with your platform: If you have an own system or application, a specialized technical equipment JAAK It helps you connect your signature directly to your existing flow. Your customers sign into your own experience with all the legal validity supported.
The simple rule to choose from
If the contract can generate a dispute - for money, for services, for non-compliance - you need a Digital Signature with Validity NOM-151If you don't know the sign and you need to know who you are before you sign up, you need a biometric version. The simple signature's only suitable if the consequences of a dispute are minimal.