How to sign a PDF electronically (and prove it later)

Signing a PDF takes a minute. Signing it in a way you can prove later takes the same minute if you choose the right method first.

There are three ways to put a signature on a PDF. They look the same on the page and are very different on the day someone asks you to prove it.

The three methods

Method	How it works	What it proves	Good for

|---|---|---|---|

Stamp a signature image	Draw or type your name and place it on the page in a PDF editor	Almost nothing — the image can be copied to another file	Your own records, low-stakes forms
Send it for signature	Upload the PDF, add the other party's email, place fields; they sign through a private link	Who was asked, how they proved it, what they saw, and that the file has not changed	Anything with another party: contracts, offer letters, NDAs, approvals

Signing a PDF yourself

For a document only you need to sign — a form, an acknowledgement, your own copy of something:

1. Open the PDF in a signing tool that runs on your device.
2. Add your signature where the form asks for it, and fill any date or name fields.
3. Save a flattened copy so the fields cannot be edited later.
4. If the document matters, seal it or sign it with a certificate so later changes are detectable.

Getting a PDF signed by someone else

For anything the other party has to agree to:

1. Upload the PDF and add each recipient's name and email address.
2. Set the order if it matters — for example, the other party signs before your approver countersigns.
3. Place signature, initial and date fields for each recipient. Fields that belong to one person should only be fillable by that person.
4. Choose the identity check. An emailed link suits most business documents; add a passcode sent separately for anything you might have to defend.
5. Send. Recipients open the link and sign; they do not need an account.
6. When everyone has signed, every party gets the completed PDF, a certificate of completion and the evidence of what happened.

Mistakes that come back later

• Emailing a PDF, asking for a signature image back. You end up with a document whose integrity nobody can show, plus an email thread as your only evidence.
• Editing the document after the first signature. Any change after someone signs should restart signing, and a good system forces this.
• Keeping the evidence only in the vendor's portal. Download the evidence package with the signed PDF and keep them together.

What it costs

Signing a document yourself should cost nothing. Sending documents for signature usually costs per sender or per document. On Pactlyra, anything that runs on your own device — editing, filling and signing for your own records — is free, the free plan includes three sends a month, signers never need an account, and verifying a signed document is free on every plan.

Last reviewed 2026-09-26. Pactlyra produces a detailed evidence record for every completed document. Electronic signature validity depends on your jurisdiction, the document type, and how the transaction is carried out; nothing here is legal advice.