Short answer
A digital signature is a way to agree to a document online, with proof of who signed and when. In law this is called an electronic signature. It is legally valid throughout the EU, and for most business documents, such as quotes, contracts and employment agreements, a simple electronic signature backed by good evidence is enough.
What is a digital signature?
In everyday language, a digital signature is any signature you place online: typing your name, drawing with your finger or mouse, or clicking a button. What matters is not how the signature looks, but what you can prove: who signed, when, and whether the document changed afterwards.
Strictly speaking, a digital signature is a technique: a cryptographic seal based on a certificate. The law speaks of an electronic signature. Read the difference in electronic vs digital signature.
The three levels: SES, AES and QES
The European eIDAS Regulation defines three levels. The higher the level, the stricter the requirements for identifying the signer.
Simple electronic signature
Any electronic way of giving consent. Its evidential value depends on what is recorded, such as the email address, the time, the IP address and a hash of the document.
Suitable for: Quotes, order confirmations, employment agreements, rental contracts and most other business agreements.
Advanced electronic signature
Uniquely linked to the signer, capable of identifying them and reveals any later change to the document.
Suitable for: Agreements where you want extra certainty about who signed.
Qualified electronic signature
Created with a qualified certificate from a recognised trust service provider. Under eIDAS it always has the same legal effect as a handwritten signature.
Suitable for: Documents for which the law requires a stricter form.
BuiltSign provides a simple electronic signature (SES) with a complete evidence file, a timestamp and an optional SMS code or ID check. We do not offer AES or QES yet.
Is a digital signature legally binding?
Yes. The eIDAS Regulation states that an electronic signature cannot be denied legal effect as evidence just because it is electronic. In the Netherlands, article 3:15a of the Dutch Civil Code gives an electronic signature the same legal effect as a handwritten one, provided the method is reliable enough for its purpose.
Most agreements also need no particular form: they are valid as soon as both parties agree. The signature then mainly serves as evidence. Only a few documents require a stricter form by law, such as a notarial deed.
Read more about the law and the exceptions on legal validity.
How do you sign digitally?
With a signing platform such as BuiltSign it works like this:
- 1
Upload your document. Drag the PDF into your account.
- 2
Place the fields. Mark where each signer signs, initials or fills in a date.
- 3
Add signers. Enter their email addresses. Want more certainty? Turn on an SMS code or ID check.
- 4
Send and follow. Signers get a link and sign on their phone or computer, without an account. You see who has already signed.
- 5
Download the result. You get the signed document with an audit certificate attached.
Only want an image of your own signature? Use the signature maker.
How do you verify a digital signature?
An image of a signature proves little, because anyone can copy it. Look at the evidence that comes with it instead:
- an audit certificate with names, email addresses, times and IP addresses;
- a hash, the digital fingerprint of the document, so you can see whether it changed afterwards;
- a timestamp from an independent party.
If a document was signed with BuiltSign, drop the PDF on builtsign.com/verify and see right away whether it matches. See what such a certificate looks like in the sample certificate. Step by step: how to verify a digital signature.
What does a digital signature cost?
Drawing a signature yourself and pasting it into a PDF as an image is free, but records nothing. A signing platform usually costs a fixed amount per month.
With BuiltSign you pay per user, not per document, and signers always sign for free. See the pricing or try it for free first.