How to Fill, Sign & Annotate PDFs on iPhone

This guide shows you how to fill in forms, add your signature, and mark up PDFs directly on your iPhone using the built-in Markup tools. You don’t need any extra apps—everything is done through the Files app or the share sheet. You’ll learn the exact taps for each task, plus how to avoid common pitfalls like losing your annotations or saving the wrong version.

What You’ll Need

An iPhone running iOS 15 or later (the steps are similar on older versions, but the interface may look slightly different).
The PDF file saved to your iPhone, either in the Files app, in an email, or on a website.
For signing: a finger or an Apple Pencil if you have an iPad (the steps are the same on iPhone).

Step-by-Step

Open the PDF

Locate the PDF. If it’s in an email, tap the attachment and then tap the share icon (square with an arrow up) in the bottom-left corner. If it’s in Safari, tap the share icon and choose “Save to Files” first, or use the “Markup” option from the share sheet.
If the PDF is already in the Files app, simply tap it to open it in Quick Look. If it opens in a different app (like a PDF reader), tap the share icon and choose “Markup” or “Save to Files” to get to the Markup view.
Once the PDF is open in Quick Look (the standard preview), tap the Markup icon in the top-right corner. It looks like a pencil tip inside a circle.

Fill in Text Fields

If the PDF has form fields (like boxes for your name or date), tap directly on the field. A keyboard will appear, and you can type your answer.
If the field doesn’t respond to tapping, it might be a flattened form (not interactive). In that case, use the Text tool: tap the plus (+) icon at the bottom right, then choose “Text”. A text box will appear. Drag it to the correct spot and type your text.
To move the text box, tap and hold it, then drag. To resize it, drag the blue dots on the corners. To change the font or size, tap the text box and use the formatting bar at the bottom.

Add Your Signature

Tap the plus (+) icon at the bottom right, then select “Signature”.
If you’ve never created a signature, you’ll see a blank area. Use your finger to draw your signature. You can also tap the “Camera” icon to take a photo of a signature on paper, or the “Touch” icon to use a trackpad-like drawing.
Tap “Done” to save the signature. It will be stored for future PDFs.
Tap the signature you just created to place it on the PDF. It will appear in the center. Drag it to the correct line and resize it if needed by dragging the blue dots.

Annotate with Shapes and Highlights

To highlight text, tap the highlighter icon (a marker pen) in the toolbar at the bottom. Choose a color, then drag your finger over the text.
To draw freehand, tap the pen or pencil tool. Choose a color and line thickness, then draw with your finger or Apple Pencil.
To add shapes, tap the plus (+) icon, then choose “Shape”. Pick a shape (rectangle, circle, arrow, etc.) and drag it onto the page. You can adjust its size and position.
To add a note (like a sticky note), tap the plus (+) icon and choose “Note”. A small note icon will appear; tap it to type a comment.

Save and Share Your Work

When you’re done, tap “Done” in the top-left corner. This returns you to Quick Look.
Your changes are automatically saved to the original file (if it’s in Files) or to a new copy (if you opened it from Mail or Safari).
To share the annotated PDF, tap the share icon and choose how you want to send it (Mail, Messages, AirDrop, etc.).
If you want to keep the original clean, use “Save to Files” and give the copy a new name before sharing.

Common Mistakes

Not saving a copy: If you open a PDF from an email and annotate it, the changes are only saved to a temporary file. If you don’t share or save it, you’ll lose your work.
Using the wrong tool: Tapping a form field that isn’t interactive will just select the page. Use the Text tool for those cases.
Signature too small or too large: After placing your signature, you must resize it by dragging the blue dots. Many people forget and leave it tiny or covering the whole page.
Accidentally deleting annotations: If you tap an annotation, it becomes selected. If you then press delete on the keyboard, it will be removed. Be careful not to hit delete while an annotation is selected.
Not checking the final file: Always scroll through the entire PDF after editing to make sure nothing is misplaced or missing.

Tips

Use an Apple Pencil if you have one—it gives you much more control for signatures and drawing.
For a cleaner signature, practice drawing it a few times before tapping “Done” in the signature creator.
If you need to fill out the same form repeatedly, save a blank copy to Files and duplicate it each time (swipe left on the file, tap More, then Duplicate).
Use the magnifier tool (the circle with a plus) to zoom in on small text fields or signature lines. It appears when you tap and hold with the text tool.
To change the color of an annotation, tap it, then tap the color swatch in the toolbar.

Troubleshooting

My annotations aren’t saving

If you’re working on a PDF that was sent to you in Mail, the changes are only temporary until you share or save. Tap “Done”, then tap the share icon and choose “Save to Files” to keep a copy. If you’re already in Files, make sure you have permission to edit the file (it might be read-only). You can duplicate it first (swipe left, tap More, then Duplicate) and edit the copy.

The text tool won’t let me type

If you tap the Text tool and nothing happens, the keyboard might be hidden. Tap the text box again, then tap the screen to bring up the keyboard. If it still doesn’t work, close the Markup view and reopen it, or restart your iPhone.

My signature looks messy

You can redo it: tap the plus icon, choose Signature, then tap the “Clear” button (or the trash icon) and draw again. You can also create multiple signatures (e.g., one for initials) and choose the one you want each time.

The PDF won’t open in Markup

If the share sheet doesn’t show a “Markup” option, the file might be in a format that isn’t supported. Try saving it to Files first, then open it from there. If it still doesn’t work, the PDF might be corrupted—try opening it on a computer to see if it’s valid.

I can’t find my saved file

If you used “Save to Files”, check the “On My iPhone” folder or the folder you selected. If you used “Save Image” (which is for images, not PDFs), you won’t find it in Photos. PDFs are always in Files.

Frequently Asked Questions

Can I use this method on any PDF?

Yes, as long as the PDF isn’t password-protected or encrypted. If it’s a scanned document (image-based), you can still annotate it, but you can’t edit the text—you’ll need to use the drawing and text tools to add information.

Will my signature be saved for future PDFs?

Yes, once you create a signature, it’s stored in the Markup tool and available for any PDF you open on your iPhone. You can manage or delete signatures by going to Settings > General > Keyboard > Text Replacement? No, actually it’s in the Markup tool itself: tap the plus icon, then Signature, and you’ll see a list of your saved signatures.

Can I undo an annotation?

Yes, tap the undo arrow (curved left) in the top toolbar, or shake your iPhone to undo. You can also tap an annotation and press delete on the keyboard.

How do I fill a checkbox or radio button?

If the PDF has interactive checkboxes, just tap them—they’ll fill in automatically. If they’re not interactive, you can use the Text tool to type an “X” or use the drawing tool to draw a checkmark.

Can I edit a PDF after I’ve sent it?

If you send the annotated PDF, the recipient gets a copy. You can’t edit the sent copy, but you can edit the original file on your iPhone and send it again.

Is there a way to type in a PDF without the text tool?

If the PDF has actual form fields, you can tap directly on them and type. The text tool is only needed for PDFs without interactive fields.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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