Guide · Updated · By Buğra Sözeri
How to Sign a PDF on iPhone
Your iPhone can sign PDFs without any extra app. The Files app includes Markup, which lets you draw a signature once and reuse it.
Step by step
- Save the PDF to Files. If the PDF came as an email attachment, tap and hold it (or open it and tap the Share button) and choose Save to Files.
- Open the PDF in Files. Open the Files app, find the document and tap it to open the preview.
- Tap Markup. Tap the Markup button (the pen tip icon). The markup toolbar appears at the bottom of the screen.
- Add your signature. Tap the + button and choose Add Signature. Draw your signature with your finger and tap Done. Saved signatures appear in the same menu next time.
- Position it. Drag the signature onto the signature line and pinch or drag the corners to resize it. Use the Text option under + to add the date if needed.
- Tap Done. Tap Done to save the changes. The signed PDF is saved in place, ready to share from the Share button.
Signing from Mail
Markup is available in several built-in apps, including Mail. When composing a message with a PDF attached, you can often open the attachment and use Markup to sign it before sending.
A browser-based option
If you would rather not install anything, eSignSimple's free Sign PDF tool is included with a free account (sign up with Google) and runs in your browser. You upload the PDF (it is encrypted at rest), draw or type a signature, add the date, and download the signed copy with an audit trail; it counts as one of your monthly documents.
It works in Safari on iPhone, which is handy when the file lives in a cloud drive or you are on someone else's device.
What if the Markup button is missing?
Markup only appears for files iOS can preview. If you opened the PDF inside a third-party app (a banking app, a cloud drive app or a messenger), use its Share button, choose Save to Files, and open the copy in the Files app instead. If the file is a Word document rather than a PDF, Markup cannot sign it; see how to sign a Word document online.
If your signature looks shaky, turn the phone sideways before drawing: the signature pad gets wider and strokes come out smoother. Draw a little slower than you would on paper.
iPhone Markup vs. an e-signature service
Markup signs your copy. It does not tell anyone when you signed or prove it was you, and the signed PDF can be edited again later. When the document matters (a lease, a job offer, a client contract), the sender will often use a service that emails you a link. Signing through that link on your iPhone takes the same minute, and both sides end up with a certificate that records the signing. Our guide on what an audit trail is explains what gets recorded.
The same steps work on iPad, with Apple Pencil for a cleaner line, and they are the quickest way to sign a PDF without printing when you are away from a desk. On a Mac, the equivalent tool lives in Preview; see how to sign a PDF on Mac.
Why does my signature look tiny or huge on the page?
Markup places your signature at a default size that rarely matches the line you are signing on. A signature drawn edge to edge in the signature pad can land on a dense form looking like it was written in marker, while a small one can shrink to an unreadable squiggle. Pinch-zoom into the page first so the signature line fills a good part of the screen, then drag the corner handles until the signature is roughly as tall as the printed text around it.
Zooming in also makes it easier to put the signature exactly on the line instead of floating above it. If you misplace it, tap the signature once to select it and drag it again; to start over, select it and choose Delete from the small menu that appears. Nothing is final until you tap Done.
Signing a PDF from a cloud drive, WhatsApp or a banking app
Plenty of documents never touch the Files app: they arrive in WhatsApp, sit in Google Drive or Dropbox, or are generated inside a banking or HR app. In almost every case the route is the same. Open the document, tap Share, choose Save to Files, sign the saved copy with Markup, then share the signed copy back through the same app. Avoid signing inside the third-party app's own preview unless you are sure it saves your changes; many of them show a Markup-like toolbar but send the original file.
Google Drive and Dropbox can also appear as locations inside the Files app if their apps are installed and enabled, so you may be able to open the PDF directly from there. Either way, check the file you send back by opening it once from the chat or the drive. For Drive-specific steps, see how to sign a PDF in Google Drive.
Signing someone else's document on your iPhone: what the signer actually sees
If a landlord, employer or client sent you a signing link, you do not need Markup at all. The link opens in Safari (or whichever browser you use), the document shows page by page, and each place you need to act is highlighted. Tap a signature field and you can draw with your finger or type your name; tap a date or text field and the keyboard appears. When every required field is filled, you confirm and you are done.
Two tips from the support inbox. First, if the page feels cramped, turn the phone sideways while signing; the drawing pad gets wider. Second, if you tap the link from a mail app's built-in browser and something does not load, open the link in Safari instead. Once everyone has signed, the completed PDF arrives by email and you can save it to Files like any other attachment.
How to keep signed PDFs organised on your iPhone
Signing on a phone makes it easy to end up with five copies called "Document.pdf". Make a folder in Files, for example "Signed 2026", and rename every signed copy with the counterparty and date before you send it: "Acme-NDA-2026-10-30-signed.pdf" tells you everything without opening the file. Long-press a file in Files to rename or move it.
If you store files in iCloud Drive, signed PDFs then appear on your Mac and iPad too, which is handy when an accountant or a landlord asks for a copy months later. For anything that matters legally, keep the copy you received from a signing service, with its certificate page, rather than a screenshot or a re-saved version.
Our take
Markup is one of the best free features on the iPhone and most people never find it. For signing a form your landlord or school emailed, it is all you need. Where it falls short is proof: the signature is a drawing on a page, nothing more. If you are the one asking someone else to sign from your phone, do not email a PDF and hope it comes back signed. Send a signing link instead, so you get a timestamped record rather than a screenshot.
Sources and further reading
Frequently asked questions
Do I need an app to sign a PDF on iPhone?
No. The Files app and Markup are built into iOS and are free.
Can I use Apple Pencil?
On iPad, yes. On iPhone you draw with your finger.
How do I delete a saved signature?
In Markup, tap + then Add Signature, and use the edit or minus option to remove a saved signature.
Can I send a PDF to someone else to sign from my iPhone?
You can email it to them, but to track signing and keep an audit trail you need an e-signature service. eSignSimple does this on every plan, including Free (3 documents a month), and signers do not need an account.
Why did my signed PDF lose the signature when I sent it?
Some apps send the original rather than the edited file. Share the PDF directly from the Files app after tapping Done, and open the sent copy to check the signature is there.
Can I fill in form fields on iPhone too?
Yes. Many fillable PDFs let you tap a field in the Files preview and type. For flat PDFs, add text boxes from the + menu in Markup.
Can I sign a PDF on iPhone without saving it to Files?
Sometimes. Mail's attachment preview offers Markup when you reply with the file, and some apps show it too. Saving to Files first is the most reliable route because you always know where the signed copy is.
My iPhone signature looks pixelated in the PDF. Why?
The signature was probably scaled up from a small drawing. Delete it, draw it again larger in landscape mode, and size it down on the page instead of up.
Can I sign the same PDF again after tapping Done?
Yes. Reopen the file in Files and tap Markup; previous signatures stay in place as long as the file has not been flattened, so you can add or remove one.
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