People download apps like Adobe Fill & Sign or SignEasy without realizing iOS already does this natively. The tool is called Markup, and once you know where to find it, you'll use it for everything.

Signing a PDF Attached to an Email

This is the most common scenario, someone sends you a PDF to sign and you need to sign it and send it back.

  1. Open the email in Mail and tap the PDF attachment to preview it.
  2. Tap the pen icon in the top right corner (the Markup icon).
  3. Tap the + button at the bottom right of the toolbar.
  4. Select Signature from the popup menu.
  5. If this is your first time: tap Add or Remove Signature → tap + → draw your signature with your finger → tap Done.
  6. Tap your saved signature to insert it, then drag it to the correct position and resize as needed.
  7. Tap Done in the top right → choose how you want to share it back (usually "Reply to Email" or "Save to Files").

Signing a PDF from the Files App

  1. Open Files and find your PDF.
  2. Tap the PDF to open it.
  3. Tap the pen icon in the top right → the Markup toolbar appears.
  4. Tap + → Signature → place your saved signature (or create one if you haven't yet).
  5. Tap Done → the file saves automatically.

How to Create Your Signature (One-Time Setup)

The first time you go to add a signature in Markup, you'll need to draw it. Here's how to make it look good:

  • Use the tip of your finger, not the pad, it's more precise
  • Sign slowly, the app captures exactly what you draw, so rushing leads to a messy result
  • If it doesn't look right, tap Clear and try again, you can redo it as many times as you want before tapping Done
  • An Apple Pencil gives much better results on iPad if you have one

Once saved, your signature syncs across all your Apple devices via iCloud. You'll see it available in Markup on your Mac and iPad too.

Signing PDFs in Safari (Downloaded Files)

If you download a PDF from a website in Safari:

  1. Tap the PDF preview in Safari → tap the Share button (the box with an arrow pointing up).
  2. Tap Markup in the share sheet.
  3. Add your signature as above.
  4. Tap Done → Save File To... to save a copy, or Share to send it immediately.

Signing PDFs in Third-Party Apps

Most iOS apps that display PDFs support Markup too, including iBooks/Books, Dropbox, and many others. Look for the pen icon or "Annotate" option in the app's share menu. If you can't find Markup there, save the file to Files first, then sign it there.

Moving and Resizing Your Signature

Once your signature is placed on the document:

  • Drag it with one finger to reposition
  • Pinch or spread with two fingers to resize
  • Rotate with two fingers if the document is oriented differently
  • Tap the signature and then the trash icon to delete and start over

Limitation to know: Markup embeds the signature as an annotation, not a "flat" embedded image. Some PDF viewers will show it as an annotation layer, and it's technically possible for someone to remove it. For important contracts, use a service like DocuSign that provides cryptographic verification. For everyday documents, Markup is completely fine.

Quick Tip: Use a Transparent PNG Signature

If your drawn signature in Markup doesn't look as clean as you'd like, another option is to create a high-quality transparent PNG on SignatureHub, save it to your iPhone's Photos, and then in Markup choose + → Photo to insert it as an image. You can then position and resize it just like a drawn signature, and it'll look cleaner than finger-drawing on a small screen.

Create a Clean Signature for iPhone

Draw or type your signature on a bigger screen, download the transparent PNG, and save it to your iPhone Photos for use in Markup.

Create Signature – Free