---
id: KB-CO-002
url: https://app.codecontract.io/help/consigne/simple-or-advanced-signature-which-to-choose
idioma: en
categoria: consigne
subcategoria: firmantes
modulo: consigne
audiencia: usuario
actualizado: 2026-08-12
tambienEn: [es]
relacionados: [KB-CO-001, KB-CO-004]
citadoPor: [KB-CO-001, KB-CO-003, KB-CO-004, KB-CO-005, KB-CR-003, KB-SC-018]
---

# Simple or advanced signature: which to choose

_The two available levels, how they actually differ and when each one is worth it._

**Responde a:** difference between simple and advanced signature · which electronic signature level do I need · signature with SMS OTP · is a simple electronic signature legally valid

The difference between the two levels is not the look of the signature — that is the same — but how much is checked about whether the signer is who they claim to be. And that is exactly what gets argued about if someone ever denies having signed.

**En corto**

- Simple: the person draws their signature. Where and when they did it is recorded.
- Advanced: they must also enter a code sent to their mobile.
- The cost of advanced is one SMS and thirty extra seconds for the signer.
- Reasonable doubt is the only thing that decides: could this end up disputed?

## How they differ

| What to look at | Simple signature | Advanced signature |
| --- | --- | --- |
| What the signer does | Draws their signature with a finger or mouse | The same, plus typing a code received by SMS |
| What gets verified | That whoever opened the link signed | Also that they control that mobile number |
| What you need from them | An email or a phone | A valid mobile, necessarily |
| How long it takes | Under a minute | About a minute and a half |
| Where it fits | Acknowledgements, consents, internal documents | Contracts, NDAs, agreements with money involved |

## How to decide without agonising

Ask yourself one question: if in two years this person said "I never signed that", would I care? If nothing much would happen, simple signature. If you would have a problem, advanced.

> [!NOTE]
> It is chosen per signer, not per document. You can require advanced from the client and simple from the person on your team who signs off.

## What is NOT supported today

Worth knowing before promising it to a client: there is no qualified signature with a certificate (the equivalent of signing with a national eID or a certificate authority), no identity verification by photographing an ID document, and no authenticator-app codes. The available levels are the two above.

## Frequently asked questions

**Is a simple signature legally valid?**

Yes — an electronic signature cannot be rejected merely for being electronic. What changes between levels is how easy it is to defend if somebody disputes it.

**What if the signer has no mobile?**

Then they cannot complete an advanced signature, because the code goes by SMS. For that person you have to use a simple signature.

**Can I change the level after sending?**

Not on a request already sent. You would cancel it and create a new one with the right level.

**Does the SMS code expire?**

Yes, it is short-lived for security. If it lapses, the signer can request another from the same link.

## Ejemplos

**A sales rep closes a €40,000 contract with a new client they have never met in person.**

- Sets advanced signature for the client's signer
- Leaves simple signature for the internal manager signing off
- Checks the client's mobile number before sending

→ If the client ever disputed the contract, there is a record that the code reached their mobile and was used to sign.

**The highest level is required for everything by default.**

- Checks which documents genuinely need it

→ The rest is signed the same day.

**A supplier cannot obtain a certificate and the process halts.**

- Separates what needs the high level from what does not

→ What can move, moves.

**Nobody knows what proof each level leaves.**

- Compares what is recorded in each case

→ The choice rests on the real difference.

**A low level is chosen for a document with a lot at stake.**

- Raises the level where the risk justifies it

→ The level matches the document's value.

**The level is changed midway through a process.**

- Decides the level before sending

→ Nothing has to be cancelled and resent.