Is an electronic signature legally binding? (EU eIDAS, UK and US)

Leases, quotes, employment contracts, purchase orders, NDAs: more and more documents are signed without paper or pen. One question keeps coming back: does an electronic signature carry the same weight as a handwritten one? The short answer is yes in the vast majority of situations, but it depends on the level of signature used and on what you need to prove if there is ever a dispute.

This guide summarises the European framework (eIDAS), the main rules in the UK and the United States, the three levels of electronic signature, and how to sign a PDF properly for each kind of document.

This article is general information, not legal advice. For high-stakes documents, consult a lawyer.

The European framework: the eIDAS Regulation

EU Regulation No 910/2014, known as eIDAS, applies directly in every EU member state. It was amended in 2024 by Regulation (EU) 2024/1183, which notably prepares the European Digital Identity Wallet. For electronic signatures, the key principle fits in one sentence: an electronic signature cannot be denied legal effect or rejected as evidence in court solely because it is electronic.

The regulation defines three levels, from the simplest to the most demanding.

The three levels of electronic signature

1. Simple electronic signature

This is the most common form: a signature drawn with a mouse or finger, a typed name, an image of a signature placed on a PDF, an "I agree" box combined with some identification.

• Legal weight: it has legal effect and can be produced as evidence. If it is challenged, the party relying on it has to show who signed and that the document was not altered.
• Typical uses: quotes, purchase orders, NDAs, internal approvals, rental applications, consent forms, most everyday commercial agreements.

2. Advanced electronic signature (AES)

It must meet four requirements: be uniquely linked to the signer, be capable of identifying them, be created using means under their sole control, and be linked to the signed data so that any later change is detectable.

• Legal weight: stronger in practice, because the signer's identity and the document's integrity are better established.
• Typical uses: significant commercial contracts, employment contracts, documents with financial stakes.

3. Qualified electronic signature (QES)

An advanced signature created with a qualified signature creation device and based on a qualified certificate issued by a qualified trust service provider after verifying the signer's identity.

• Legal weight: the same legal effect as a handwritten signature, recognised as such in every EU member state.
• Typical uses: documents where the law or the other party requires this level, some regulated or administrative procedures.

The United Kingdom

After Brexit, the UK kept the eIDAS concepts in its own law (often called "UK eIDAS"), alongside the Electronic Communications Act 2000. English law generally accepts electronic signatures, including typed names and drawn signatures, where there is an intention to authenticate the document. Some documents, such as certain deeds, have extra formalities like witnessing.

The United States

In the US, the federal ESIGN Act (2000) and the Uniform Electronic Transactions Act (UETA), adopted by almost every state, provide that a signature, contract or record cannot be denied legal effect solely because it is electronic. There is no "qualified" tier as in the EU; what matters is showing intent to sign, consent to do business electronically and a reliable record of the signed document. A few documents, such as wills in many states, are excluded or have specific rules.

Which signature should you use?

Document	Level usually sufficient
Quote, purchase order, NDA	Simple
Rental application, consent form, certificate	Simple
Major commercial contract, employment contract	Simple or advanced depending on the stakes
Document legally requiring a specific level	Qualified (EU)

The right question is not only "is it legal?", but "what will I need to prove if the other party disputes it?". The higher the stakes, the more useful it is to be able to establish the signer's identity and the integrity of the document.

How to sign a PDF with PDFtoWorld

PDFtoWorld offers several tools depending on the level of evidence you need:

• Sign PDF: draw, type or upload your signature and place it anywhere on the document. This is a simple electronic signature, ideal for everyday documents.
• Request Signatures: send a PDF to be signed by email; signers sign online on any device and everyone receives the signed copy.
• Digital Signature PDF: sign cryptographically with your own certificate (.p12 or .pfx file). The signature can be verified in PDF readers, and any later change to the document invalidates it. Its legal level depends on the certificate used: a qualified signature requires a qualified certificate and a qualified creation device.

Sign a PDF in four steps

1. Open Sign PDF and drop your document.
2. Create your signature: Draw, Type or Upload, then Use signature.
3. Place it where needed, adjust its size, and add the date or a short statement with the Text tool if required.
4. Save the signed document.

Keep your evidence

Whatever the signature level, a few habits strengthen your position in case of disagreement:

• keep the email that sent the document and the email that returned it signed, with their dates;
• keep the exact final version of the PDF, without changing it after signing;
• for important contracts, prefer a signature that makes any change detectable (digital signature with a certificate);
• archive the document somewhere safe and backed up.

Frequently asked questions

Is a scanned signature pasted onto a PDF valid?

It is a simple electronic signature: it is not without legal effect, but it is easy to copy. For an important document, prefer a method that proves who signed and that the document has not changed.

Is an electronic signature recognised across the EU?

Yes, eIDAS applies in every member state. A qualified signature issued in one EU country is recognised as such in all the others.

Can an employment contract be signed electronically?

Yes, it is common practice in the EU, the UK and the US. Make sure you can prove the employee's identity and the signed version, and give them a copy.

Do I need software to sign a PDF?

No. Everything happens in your browser, on a computer or a phone, with Sign PDF.