Does an online signature drive hold up legally?

Two things need separating. The electronic signature itself is valid: in the United States it rests on ESIGN and the UETA, in the European Union on eIDAS, and elsewhere on the laws based on the UNCITRAL Model Law. What is different is an official procedure with requirements of its own — a ballot initiative, say — where what that rule demands is what counts, and it is worth reading before you start. This is not legal advice.

What does it take to present it to a public body?

There they usually want to know who signed, not just how many. That is what the advanced signature is for: beyond the email, the signer's identity is checked against their document, and every anchoring is recorded one by one.

What if whoever receives it does not trust you?

All the better, because they do not have to. Every signature comes out with its certificate, and its fingerprint is anchored on a public blockchain: anyone can check that the certificate is the one that was issued and that it has not been touched, without an account and without asking us.

What is asked of the signer, and who sees it?

The least that makes the signature worth something, and it is set out in full on this same page, under «Who sees what». The list of signers is not published, sold or passed to anyone.

Creating the cause, publishing it and collecting simple signatures cost nothing, and there is no cap on signatures. The advanced signature, which checks identity against a document, is priced per signature, and you are told the amount before anything is switched on.

Which countries can people sign from?

Any of them. Collecting signatures needs nobody in the middle, so it depends neither on the country of whoever creates the cause nor on that of whoever signs.

A petition is not one click

Everyone who signs your cause gets a certificate of their signature. You get a record you can present. And anyone can check that nothing has been touched.

Start a cause

From opening the cause to holding the record

Four steps, and the one that decides is none of the technical ones: it is how many people your link reaches.

You open the causeYou say what you are asking for, who you are asking and why. Creating it, publishing it and keeping it open cost nothing, and there is no cap on signatures.
You choose how much gets verifiedSimple signature, with the email confirmed, or advanced signature, with identity checked against a document. It depends on who you are going to present it to.
Every signature is confirmed and leaves its certificateIt is not pressing a button. The signer confirms their email, receives a certificate of their own, and the fingerprint of that certificate is anchored on a public blockchain.
You take the record with youA record you can present, and one that whoever receives it can check for themselves, signature by signature, without an account and without asking us.

Depending on what you need to prove

Not every cause needs the same. You choose how much the signer is verified.

To mobilise and show support

We verify the email exists and belongs to them. It is what most causes use, and it is free.

Email verification
A certificate for every signature
Proof anchoring

For when you have to present it to someone

On top of the email, the person’s identity is verified with their ID document. Used when the cause is aimed at a public body or an organisation that will demand guarantees.

Everything in the simple signature
Identity verification with ID document
Individual anchoring record

Suited to many different needs.

What this proves

The email is theirs

There is a real email behind the signature.

Sealed by Causfy

Every certificate carries an electronic seal proving who issued it and that it has not been altered. Its fingerprint (SHA-256) is anchored on a public blockchain, so anyone can check its integrity on their own, without depending on us.

Internationally valid

Also recognised by the electronic signature laws based on the UNCITRAL Model Law, in force in most countries.

A signature nobody can alter afterwards

You do not have to take our word for it. The proof lives outside our servers.

Signed and verified

A simple, intuitive process, within reach of anyone.

The document is sealed

A certificate is issued with a corporate seal, and its fingerprint is calculated.

The fingerprint is anchored on a blockchain

Only that fingerprint is written to a public blockchain, as an immutable mark nobody can rewrite.

Example

document: certificado-firma-4821.pdf sealed
fingerprint: b4c45f126c32961fdb8cb8672f6561f7630aab9d8d0f1e08867410f73938b122
anchored: public blockchain · 2026-09-06 11:42 UTC

Nobody’s data goes on the chain. What gets published is an irreversible fingerprint: a fixed-length cryptographic digest, with no personal data.

Check a certificate

Who sees what

We say it here and not in the small print, because whoever signs has a right to know beforehand.

The signer: Gets their certificate and can download it whenever they want.
Whoever created the cause: Gets the record of who has signed. They need it to present the cause.
Any visitor: Sees how many people have signed. No names, no emails.
The public blockchain: Holds only fingerprints. No names, no emails, no documents.

Built to scale

Designed for high concurrency.

It keeps performance steady even when demand spikes.

What people ask before opening a signature drive

Does an online signature drive hold up legally?: Two things need separating. The electronic signature itself is valid: in the United States it rests on ESIGN and the UETA, in the European Union on eIDAS, and elsewhere on the laws based on the UNCITRAL Model Law. What is different is an official procedure with requirements of its own — a ballot initiative, say — where what that rule demands is what counts, and it is worth reading before you start. This is not legal advice.
What does it take to present it to a public body?: There they usually want to know who signed, not just how many. That is what the advanced signature is for: beyond the email, the signer's identity is checked against their document, and every anchoring is recorded one by one.
What if whoever receives it does not trust you?: All the better, because they do not have to. Every signature comes out with its certificate, and its fingerprint is anchored on a public blockchain: anyone can check that the certificate is the one that was issued and that it has not been touched, without an account and without asking us.
What is asked of the signer, and who sees it?: The least that makes the signature worth something, and it is set out in full on this same page, under «Who sees what». The list of signers is not published, sold or passed to anyone.
What does it cost?: Creating the cause, publishing it and collecting simple signatures cost nothing, and there is no cap on signatures. The advanced signature, which checks identity against a document, is priced per signature, and you are told the amount before anything is switched on.
Which countries can people sign from?: Any of them. Collecting signatures needs nobody in the middle, so it depends neither on the country of whoever creates the cause nor on that of whoever signs.

You can try the certificate verifier right now, without having a cause. And if what you need is not support but money, that is fundraising.

Open your petition cause

No cost and no cap on signatures.

Start a cause

Latest posts

See all posts

A petition is not one click

From opening the cause to holding the record