How to Sign a PDF on iPhone
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Signing a PDF on an iPhone is one of those tasks iOS almost handles for you. The built-in Markup tool can add a signature in a pinch, and for a quick, one-off signature it's genuinely fine. But the moment you're signing regularly — contracts, forms, agreements that come back week after week — its limits start to show, and a dedicated tool saves real time.
This guide covers both routes. First the native Markup approach using the Files app, with an honest look at where it falls short. Then the PDF Editor app, which saves a reusable signature, detects signature fields, and keeps everything on-device.
Electronic signatures are accepted for ordinary business documents in most places, so signing on your iPhone is rarely just a convenience — it's often perfectly sufficient on its own.
Step by step
- 1
Quick route: open the PDF in Files
Tap the PDF in the Files app to open it, then tap the Markup (pen tip) icon. This is iOS's built-in editor — handy for a one-off signature with nothing to install.
- 2
Add a signature with Markup
Tap the plus button, choose Signature, and draw one with your finger or save a new one. Place it on the page and resize it. Good enough for the occasional document.
- 3
Know where Markup runs out
Markup can't detect form signature fields, doesn't handle dates or initials cleanly, and re-drawing or re-finding your signature each time gets old. For frequent signing, move to a dedicated tool.
- 4
Better route: open it in the PDF Editor app
Import the PDF into the app from Files, Mail, or any share sheet. The Sign tool offers handwritten, typed, and initials options.
- 5
Draw your signature once, reuse it forever
Create your signature the first time — finger or Apple Pencil — and it's saved on your device for every future document. Signing then becomes open, tap, place, export.
- 6
Place, date and export
Drop the signature where it belongs, add a date stamp or initials if the document needs them, and export a signed copy. Save it as a new file so the unsigned original stays intact.
Tips
- Use an Apple Pencil if you have one — the stroke is noticeably cleaner than a fingertip, which matters for client-facing contracts.
- Markup is the right tool for a true one-off. If you'll sign more than once a month, a saved, reusable signature pays for itself fast.
- Keep the unsigned original alongside the signed copy. If a counterparty wants a clean version or you need to re-sign with a correction, you'll have it.
- For a sensitive signed document, add a password before sharing — signing and protecting are separate steps.
- An electronic signature suits ordinary business documents, but high-value or regulated agreements may require a more formal qualified signature — check the rules for those.
Try it on your phone
Signing on an iPhone means a contract goes back within the hour, often within minutes. The PDF Editor app keeps your saved signature on-device, detects existing signature fields, and never uploads the document — so even sensitive agreements stay private while you sign on the move.
