How to sign a PDF document

Signing a PDF is easy. The question that actually matters is whether the signature you just applied will be accepted by whoever receives it — and that depends on a distinction the phrase “electronic signature” hides. This guide covers both: the practical steps, and the honest boundary between a signature that works for everyday business and one that a registry or a court will insist on.

Two very different things share one name

A visual signature is an image of your handwriting, or typed text, placed on the page and permanently merged into the PDF when you save. That is what this tool produces. It looks exactly like a signature applied to a printed page and scanned back in, because functionally that is what it is.

A cryptographic digital signature is something else entirely: a certificate issued by a certification authority that identifies the signer, a cryptographic hash that reveals any later alteration to the document, and a timestamp from a trusted third party. This is the kind covered by eIDAS in the European Union and applied through services like DocuSign or Adobe Sign.

A PDF signed here contains none of the second sort. There is no certificate, no identity verification, no tamper-evident seal and no audit trail recording who signed, when and from where. That is a real limitation, and the trade-off is that nothing about your document — including the fact that it exists — is known to any third party.

None of what follows is legal advice. Rules differ by country and by document type, and where money or property is involved the recipient's requirements decide, not an article.

Where a drawn signature is normal practice

In everyday business a great many documents are exchanged and honored with exactly this kind of signature. Under general contract law in most jurisdictions a signature is a mark made with the intent to be bound, and the form of the mark matters far less than that intent and the evidence around it. A scanned signature returned on a PDF has been the default in business correspondence for two decades. Typical cases:

• Internal paperwork — timesheets, expense claims, leave requests, confirmation that you have read a policy.
• Onboarding packets and routine HR forms that go back to a colleague rather than to a registry.
• Commercial agreements between parties who already know each other and simply need the file back today.
• School and university forms, permission slips and applications submitted through a web portal.
• Delivery notes, invoices, quotes and letters, where the signature confirms authorship rather than proving identity.
• Rental and service agreements where both sides are content to exchange signed PDFs.

Where it is not enough

Do not use a visual signature where an identity-verified signature is a legal requirement. The recurring categories:

• Property transfers and land registry filings. Registries verify identity; an image on a page does not.
• Anything notarized. The notary's job is to witness the act of signing, which cannot be delegated to a graphics editor.
• Court filings. Most systems have their own e-filing rules and their own accepted signature formats.
• Regulated finance and public procurement. Banks' compliance departments and tender portals routinely specify a qualified electronic signature by name.
• Anything where the counterparty has asked for a qualified or advanced electronic signature. If they said it, they mean it, and a drawn signature will be sent back.

How to sign the document

Open Sign PDF, load your document and go to the page that needs signing. From there it is three steps.

1. Draw or insert the signature. Choose the brush and draw with a mouse, stylus or finger, or insert a photo of a signature you already have.
2. Fill in what the form asks for. Use the text tool for a printed name, a date, a job title or a place of signing. Non-Latin alphabets are embedded properly rather than dropped.
3. Position, resize and download. Drag the signature onto the signature line, size it, and save. The mark is written into the page itself.

Everything happens inside your browser: the PDF is opened locally, the signature is drawn onto the page locally, and the signed file is written back to your device. No one, including us, ever has a copy of what you signed — which is the whole point when the document is an employment contract or a settlement. One thing worth doing before you sign: if the version going round is still a draft, mark it with watermark PDF instead, because a signature on an unmarked page is read as final.

Making it look like a signature, not a paste

A touchscreen with a finger or a stylus gives the most natural result, because your hand moves the way it does on paper. A mouse does not, and mouse-drawn signatures come out wobbly and obviously digital. If you are on a desktop and the result is unconvincing, sign a blank sheet of white paper with a black pen, photograph it and insert that image instead. That is also how you reuse one signature across many documents — keep the image file somewhere private, since a clean signature image is worth protecting.

A few details separate a document that looks signed from one that looks tampered with:

• Keep the signature roughly the size a real one would be on paper. A signature spanning the width of the page reads as a graphic, not a signature.
• Place it on the signature line, not across it or floating above it.
• Fill in the printed name, date and place if the form has fields for them. An unlabeled squiggle raises more questions than it answers.
• On a multi-page document, check whether the recipient expects initials on every page.
• Zoom in before you draw on a phone, so the mark lands where it should rather than approximately there.

Once saved, the signature is part of the page and cannot be dragged off or edited in an ordinary PDF reader. Keep the unsigned original in case the document has to be reissued. From here you can merge PDF to attach exhibits, add page numbers before the file goes out for review, or compress PDF if the signed copy is too heavy to email. If what you were sent is a stack of photographed pages rather than a PDF, convert them first with JPG to PDF.

Common questions

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