How to add a legally binding signature to a PDF

A legally binding signature needs three things: intent to sign, a verified identity, and a tamper-evident record. PDF Verified captures all three automatically, a click-to-sign action with timestamps, verified signer identity, and a cryptographic seal, so your signed PDF stands up as evidence.

Sign PDF online → · Free PDF Signer

What you can do

How to add a legally binding signature to a PDF

  1. Open the free signer and drag your PDF in, or tap to choose a file, no account needed.
  2. Draw, type or upload your signature, then drop it exactly where it belongs. Add the date, initials or text fields too.
  3. Click seal, PDF Verified binds the signature to the document with a tamper-evident cryptographic hash and an audit trail.
  4. Download the signed PDF or share a verification link. Anyone can confirm it is genuine and unaltered.

Ready? Sign PDF online now, free, no signup, and your file is auto-deleted after an hour.

Frequently asked questions

What makes an electronic signature legally binding?

Courts look for intent to sign, the identity of the signer, and the integrity of the document. PDF Verified records the signing action and timestamp, verifies identity, and seals the file with a SHA-256 hash, then issues an audit certificate documenting all three.

Will a court accept an electronically signed contract?

Courts across the US, EU, UK and most of the world routinely accept them, and the statutes say a signature cannot be refused legal effect merely for being electronic. What a court then weighs is the evidence: who signed, that they meant to, and that the document has not changed since. That is what the audit certificate is for. Whether a particular court accepts a particular document is a question about that document, not about electronic signing in general, so take advice where the outcome matters.

Are electronic signatures legally binding in court?

Courts across the US, EU, UK and most of the world routinely accept them, and the statutes say a signature cannot be refused legal effect merely for being electronic. What a court weighs is the evidence around it: who signed, that they meant to, and that the document has not changed. Whether a particular court accepts a particular document is a question about that document, so take advice where the outcome matters.

What is the difference between an electronic signature and a digital signature?

An electronic signature is the legal idea: any electronic mark made with intent to sign, from a typed name to a drawn one. A digital signature is a specific technology: a cryptographic operation using a certificate and a private key, which produces a mathematical proof of who signed and that the bytes have not changed. Every digital signature is an electronic signature; most electronic signatures are not digital signatures. In everyday speech the two are used interchangeably, and in Argentina, Italy and India they are separate legal categories with different consequences.

Do I need a witness to sign electronically?

For most commercial documents, no. Some document types do carry a witnessing or attestation requirement, deeds in England and Wales among them, and the rules on remote witnessing differ by jurisdiction and have changed several times. A witness can sign electronically where the law allows electronic witnessing, and cannot where it does not. This is a check-locally question rather than a product question.

Does an electronic signature need to be notarised?

Only where the document itself needs notarising, which is a separate requirement from signing. Where notarisation is required, some jurisdictions now permit remote online notarisation and others still require appearance in person. Notarising is a service a notary provides, not something a signing tool can do for you.

Is a typed signature legally binding?

It can be. What matters legally is intent, not the shape of the mark: a typed name applied deliberately to a document as a signature is a signature in most jurisdictions. What a typed name lacks is any evidence of who typed it, which is why the record around it, timestamps, identity checks and a document seal, is doing the real work.

Is a scanned signature legally binding?

A scanned signature pasted onto a document has the same weakness as a typed one, and one more besides: the image can be lifted from one document and dropped onto another, and nothing about it says which document it was made for. It is not worthless, but it is the weakest form, and it is the reason a sealed signature with an audit trail is worth more than a picture of a pen stroke.

Is a PDF signature legally binding?

A PDF signature is legally binding on the same terms as any other electronic signature: it depends on intent, identity and integrity, not on the file format. What a PDF adds is that the document can be sealed, so the version signed is fixed and any later change is detectable. That is evidence, and evidence is what the format contributes.

What is an audit trail on a signed document?

It is the record of what happened around the signature: who opened the document and when, from what address, which verification steps they passed, when each party signed, and the fingerprint of the exact file they signed. It is issued as a certificate alongside the document. Without one, a signature is a mark on a page with nothing behind it; with one, there is something to produce when somebody asks.

How do I prove a document was not altered after signing?

By its fingerprint. A SHA-256 hash of the finished file is recorded at signing, and any change at all, one character, one pixel, produces a completely different hash. To prove a document was not altered, recompute the hash of the file you hold and compare it to the sealed value: that is what the verification page does when somebody scans the QR code or uploads the file.

How long should I keep a signed document?

Long enough to cover the limitation period for a claim under it, which varies by country and by document type, and long enough to satisfy any tax or sector retention rule that applies. Six or seven years is a common floor and some records run far longer. The number depends on your jurisdiction and industry, so check it against your own rules rather than a general figure.

Can an electronic signature be forged?

Any signature can be forged, on paper or on screen, and it is worth being clear about that rather than claiming otherwise. What differs is what forgery leaves behind. A copied signature image leaves no trace at all. A sealed document records the time, the address it came from, and a fingerprint of the exact bytes, so a document altered after signing fails verification and a signature applied elsewhere does not match the record. Signing in someone else name is forgery whatever the tool, and having the authority to sign is on you.

Is it free to sign a PDF online?

Yes. You can fill in and sign a PDF for free with no account, you only pay when you download a finished document ($1.50 per document pay-as-you-go, or unlimited on any paid plan). a legally binding signature works the same way.

Is signing a PDF online secure?

Yes. Files are uploaded over 256-bit TLS, processed in your browser session, and automatically deleted after one hour. Each signature is bound to the document with a SHA-256 tamper-evident seal, so any later edit is detectable.

Are electronic signatures legally binding?

Yes, electronic signatures are legally binding for ordinary business documents in 190+ countries under the US ESIGN Act and UETA, the EU eIDAS Regulation, and equivalent laws worldwide. Courts look for intent, identity and integrity, all of which PDF Verified records.

Do I need to install anything?

No. Everything runs in your browser on desktop or mobile, no app, plugin or download required.

What PDF Verified is, and what it is not

Electronic signature law is settled in broad terms and specific in the details. The ESIGN Act, UETA, eIDAS and their equivalents recognise electronic signatures across more than 190 countries, and what decides a particular case is intent to sign plus evidence connecting the signature to the signer, which is what the audit certificate records. Certain document types carry their own formalities wherever you are: deeds, wills, some property instruments, and anything requiring a witness or a notary. Sign only what you are authorised to sign, since applying another person signature without their authority is forgery whatever tool is used.

PDF Verified is a tool for preparing, signing, stamping and checking documents. It is not a law firm, a compliance service or a forensic examiner, and nothing here is legal, financial or compliance advice. Requirements differ by country, by document type and by the party asking, so check what applies to your document before you rely on it, and take advice where the document matters. You are responsible for the documents you create, sign and send, and for having the authority to do so: signing or stamping in somebody else name, or as an organisation you do not represent, is forgery whatever tool is used. To the extent the law allows, we accept no liability for how a document made with this tool is used or relied on. The full position is in our terms of service.

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