To sign a document on an iPhone, open it (in Files, Mail, or Notes), tap the Add button in the Markup toolbar, tap Add Signature, sign with your finger, tap Done, then drag the signature where it belongs. You don’t need to download anything. Markup is built into the iPhone, and once you’ve made a signature it’s saved for next time.
The exact taps depend on where the document came from, so here are the three common cases, all checked against Apple’s iPhone User Guide (the current version covers iOS 27), plus what to do when Markup isn’t the right tool.
How do I sign a PDF on my iPhone?
Open the PDF in the Files app, tap the Add button, tap Add Signature, sign, tap Done, and drag the signature into place. Apple’s full steps:
- Open the form or document on your iPhone. If you’re prompted, open it in the Files app, then tap Save.
- If there are blank fields to fill in, tap the AutoFill button, tap a field and type. If a prompt appears, you may be able to fill several related fields at once and tap Fill after checking them.
- To sign, tap the Add button, tap Add Signature, sign your name with your finger, then tap Done.
- Drag your signature to where it should appear on the page.
- When you’re finished, tap the Menu button, then tap Export, Print, or the Share button to send the completed document.
Apple’s guide also mentions a tip I’d underline: rotate your iPhone sideways to get more room to sign. A finger signature drawn in a tiny portrait box tends to come out cramped. Turned sideways, it looks a lot more like the one on your driver’s license.
If you’ve filled out your My Card in the Contacts app, AutoFill can complete supported forms with your name, address and so on. Apple notes you can also choose “Choose other” to fill in someone else’s details from Contacts, which is handy for a child’s school form.
How do I sign a document someone emailed me?
In the Mail app, tap the attachment, tap the Markup button, add your signature, then tap Done and choose to reply to the sender. Apple’s guide for annotating attachments says you can “draw and write on a photo, video, or PDF attachment, then save it or send it back.” When you finish, Mail gives you four choices: reply to the attachment sender, start a new message, save the annotated attachment to your files, or discard it.
To add an actual saved signature (instead of scribbling with the pen tool), use the Add button in the Markup toolbar and tap Add Signature, the same as in Files.
There’s a second route in Mail that’s quicker for forms. Apple describes it this way:
- In the message, tap the attachment to open the document.
- Tap the AutoFill button, then tap Form Filling.
- Tap a blank field and type. Repeat for each line.
- Tap the Done button, then tap Reply to [name].
That sends the completed form straight back to whoever sent it, without saving a copy anywhere first. If you want to keep a copy for your own records (and for anything involving money, you should), touch and hold the attachment in the original email and choose Save to Files before you start.
Can I sign a PDF in Notes or Photos?
Yes. Apple lists Notes and Photos among the apps that support Markup, and in either one you can tap the Markup button, then the Add button, then Add Signature. Notes is useful when a PDF is part of something bigger. You can attach a PDF to a note from Files or Mail (drag it in, or touch and hold the file and share it to Notes), then annotate it right inside the note.
Photos matters less for signing, but it’s worth knowing that Markup works on images. If someone sends you a photo of a delivery slip and asks you to sign it, you can.
How do I save my signature so I don’t redo it every time?
You don’t have to do anything special: iPhone saves the signature you create with Markup and offers it the next time you tap Add Signature. From there:
- To add another one, tap Add or Remove Signature, then tap the Add button and sign. Apple suggests creating separate signatures for things like a nickname or your initials.
- To label a signature, tap the option next to New Signature at the top of the screen and pick a label such as given name, nickname, or initials.
- To redo one while you’re drawing it, tap Clear and sign again.
- To delete one, tap Add or Remove Signature, then tap the delete button next to the signature you want gone.
Once a signature is on the page, drag it to move it and drag any blue dot on its box to resize it.
Can I sign a Word document on my iPhone?
Not with Markup, at least not according to Apple’s own instructions, which cover PDFs and images. The cleanest fix is to ask whoever sent the Word file for a PDF. Most people can export one in a few seconds, and it also means the layout you sign is the layout they’ll keep, instead of something that reflows on a different device.
If the Word file is one you’re preparing yourself on a computer, our guide on how to insert a signature in Word covers that side, and how to electronically sign a Word document explains how to get one signed by someone else.
What if the document is on paper?
Sign the paper with a pen, then scan it with the Mail app and send it as a PDF. In a new message, tap where you want the attachment, tap the button above the keyboard, and choose Scan Document. Hold your iPhone over the page and it captures it automatically. Tap Keep Scan, add more pages if needed, then tap Save. You can crop, rotate or apply a filter before sending.
This is the right move when someone has asked specifically for a handwritten signature. If you’re unsure whether a scan will be accepted, our piece on e-signature vs wet signature explains when ink still matters.
Is a signature added with Markup good enough?
For a permission slip, a delivery confirmation or a simple agreement with someone you know, usually yes. Markup puts an image of your signature on the page, and that’s what most everyday paperwork needs.
What it doesn’t do is lock the file or record anything about the signing. Nothing shows when you signed, and nothing stops the PDF from being edited afterward. That’s fine between a parent and a soccer coach. It’s thinner for a $6,500 kitchen remodel contract where the homeowner and the contractor might later disagree about what the scope said.
If you’re on a phone that isn’t yours, or you’d rather not install anything on a work device, we also made a free Sign a PDF tool that runs in Safari, adds a typed or drawn signature and the date, and never uploads your file. Same limitation, though: it’s a signature image, not a sealed document.
When more than one person has to sign, or you need a record of who signed and when, an e-signature service is the better fit. We cover how that works in how to get a document signed by multiple people. SignWren does that: people sign on any device, including an iPhone, and everyone gets back a sealed PDF with an audit trail. You can start free.