How to Edit a PDF on iPhone: Mark Up, Sign, Fill In and Change Pages

You do not need an app to work on a PDF on an iPhone. The Files app and Mail include Markup, a set of tools for drawing, highlighting, adding text and shapes, and signing. They cover most of what people actually do on a phone: filling in a form, signing a contract, or marking a document up for someone else. What they cannot do is change text that is already printed on the page, and this guide explains how to handle that too.

The quick answer

1. Open the PDF from the Files app, from Mail, or from a message.
2. Tap the Markup button, shown as a pen tip.
3. Use the pen, highlighter or pencil to draw, or tap the plus button for Text, Signature and Shapes.
4. Tap Done and save the file, or share it from the share button.
5. Save to Files if you want to keep an edited copy.

Screens and icons change a little between versions of iOS. If you cannot find a button, look in the toolbar and the plus menu, and tap the page itself to bring up the controls.

Step by step: sign and fill in a form

Complete the form

If the PDF has fields, tap one and type. The keyboard has a bar above it that can offer information from your contacts. If the form has no fields, you will see printed blanks but nothing happens when you tap them. In that case, tap the plus button, choose Text, and place a text box on each blank. Drag it into place and resize it, and use the text style button to match the size of the printed text.

Add your signature

1. Tap the plus button in Markup and choose Add Signature.
2. Draw your signature with your finger, using landscape orientation for more room.
3. Tap Done, then drag the signature onto the signature line.
4. Pinch the corner handle to resize it so it looks like a natural signature.
5. Zoom in and check that it sits on the line and does not cover printed text.

A drawn signature is an electronic signature. Many organisations accept it for routine documents, but some documents need more, so ask if you are unsure; our guide to digital vs electronic signatures explains the difference.

Check and share

Scroll through the entire document before sending, because phone screens hide small mistakes. Then use the share button to send it, or Save to Files to keep a copy. Keep the original file untouched; most of the trouble people have with edited PDFs comes from overwriting the only copy.

Working with pages on iPhone

When a PDF has the wrong pages or the wrong order, the page thumbnails are the quickest fix. In recent versions of iOS you can open them from the toolbar and rotate a page, delete it, or insert a blank page or a scan. To combine several PDFs, a phone is workable for two or three files, and our guide to merging PDFs on iPhone, Android and desktop shows the options. For scans, the Files app can scan a document straight to a PDF, which you can then mark up.

Changing existing text from a phone

This is where Markup stops. You have three choices. The first is a browser-based editor that edits text lines and removes the original text, which keeps the layout and takes a minute for a single word or number. The second is to convert the PDF into a Word-type document and edit there, which suits big rewrites but takes tidying. The third is to use the original file. On a phone, the first is usually the most practical.

A worked example: a permission slip on the way to school

A permission slip arrives as a PDF by email, and it needs to be back in an hour. You open it from Mail, tap Markup, and add text boxes for your child's name and your phone number, matching the size of the printed labels. You draw your signature, place it on the line, and add the date. You zoom in to check each entry, then use the share button to reply with the signed copy. The whole thing takes about three minutes and needs no app.

If the slip had been a photo of paper rather than a PDF, you would first turn it into a PDF, for example with the scanner in Files, then mark it up the same way.

Problems and fixes

• Text boxes are too small to read: zoom in before placing them, and set the size in the text style options.
• Your signature looks shaky: redo it in landscape orientation with a steady hand, or use a stylus.
• Markup does not appear on a computer: a viewer may hide annotations; flatten or check in a second viewer.
• The PDF will not open for editing: it may be protected; if you know the password, unlock it first.
• The file is too big to email: compress it before sending.

For a longer view of what editing means and which tool suits which job, read what a PDF editor is, and for a Mac equivalent, how to edit a PDF on a Mac.

Getting a PDF onto your iPhone in the first place

• From Mail: open the attachment, tap it to preview, and use the Markup button in the preview, then reply with the marked-up copy.
• From Messages: tap the PDF, mark it up, and send it back in the same conversation.
• From Safari: open the PDF, tap the share button, and choose Save to Files so you can keep an editable copy.
• From paper: use the document scanner in Files or Notes to make a PDF, then mark it up.
• From a cloud service: open it in the service's app or save it to Files first.

Saving a copy to Files before you start is a good habit, because it means you always know where the edited version lives and you still have the original in the place you got it from.

Tips for iPad and Apple Pencil

On an iPad, Markup is more comfortable than on a phone: there is room for the whole page, and an Apple Pencil makes handwriting and signatures look natural. The same tools apply. Use the pencil for notes and a signature, the highlighter for passages, and the text tool for typed entries. Work in landscape for forms, and zoom in for small print. Everything in this guide applies to iPad as well, with the added benefit of a bigger screen for checking your work.

Where your files end up, and keeping them private

• Edited PDFs saved to Files may sync to iCloud Drive if you use it, so think about whether that suits sensitive documents.
• Delete temporary copies you no longer need, including in Recently Deleted.
• Add a password before emailing a document that contains personal details, following how to password protect a PDF.
• Be careful with signed forms on shared devices; remove your saved signature if someone else uses your phone.
• Keep the original file in a separate folder from your edited versions.

A short checklist

1. Open the PDF in Files or Mail and tap Markup.
2. Type, draw, highlight and sign.
3. Zoom in and check every page.
4. Save a copy and keep the original.
5. Use a browser editor or the Word route when you need to change existing text.