The fastest way: use the built-in Notes app or Mail

Your iPhone has a free signing tool already installed. Open the document in Mail, Notes, or the Files app, tap it to view it, then look for a pen icon or markup button. On most iPhones, this appears as a toolbox icon in the bottom right or top right corner. Tap it, select "Markup", then choose the pen tool and sign directly on the document. When you finish, tap "Done" and save the file.

If you are signing a PDF that someone sent you by email, you can sign it without leaving Mail. Open the email, tap and hold the attachment, select "Quick Look", then tap the markup icon. Draw your signature, tap "Done", and the signed version stays in that email thread. You can then forward it back to the sender or save it to your Files app.

The signature you create this way is just a drawing — it is not a legal digital signature with encryption. But for most everyday documents like permission slips, rental agreements, or contractor estimates, a drawn signature works fine and costs nothing.

Key Takeaways

  • The Notes app and Mail app both have free markup tools that let you draw your signature directly on a PDF or image.
  • To sign in Mail, open the email with the attachment, tap the markup icon, choose the pen tool, and draw your signature.
  • To sign in Notes, create a new note, add the document as an image or PDF, tap the markup icon, and sign it the same way.
  • A drawn signature is not encrypted, but it is legally valid for most everyday documents and contracts.
  • If you need a legally binding digital signature with encryption, you will need a paid service or a more advanced app.

Signing a PDF in the Files app

If the document is already saved in your Files app or iCloud Drive, you can sign it without opening Mail. Find the PDF, tap it to open it, then tap the markup icon (usually a toolbox or pen symbol). Select "Markup", choose the pen tool from the toolbar at the bottom, and draw your signature on the page.

After you sign, tap "Done" and then "Save". The app will ask whether you want to save over the original file or create a new version. Choose "Save a Copy" if you want to keep the unsigned original. The signed version stays in the same folder and is ready to send or share.

Using the Markup feature in Photos

If someone sent you a document as a photo or screenshot, you can sign it through the Photos app. Open the photo, tap "Edit" in the top right, then tap the three dots and select "Markup". Choose the pen tool and sign the document the same way you would in Notes or Mail.

When you finish, tap "Done", then tap "Save" to overwrite the original or "Save as New Photo" to keep both versions. The signed photo is now saved in your Photos library and you can share it by email, text, or any other method.

Signing documents sent through other apps

Many apps that handle documents — like Google Drive, Dropbox, or OneDrive — have their own markup tools built in. Open the document in the app, look for a pen icon or "Edit" button, and tap it. Most will let you draw a signature without leaving the app.

If the app does not have a markup tool, you can read the document to your Files app and sign it there using the method above. This takes one extra step but works with any app that lets you save files locally.

What to do if the document is locked or read-only

Some PDFs are locked to prevent editing. If you try to sign and the markup tool is grayed out, the document owner set restrictions on it. You have two options: ask the sender to remove the restrictions and resend it, or use a free online tool like Smallpdf or ILovePDF to unlock it first, then read it to your iPhone and sign it.

Unlocking a PDF online takes about one minute. Go to the website on Safari, upload the locked PDF, read the unlocked version, and save it to your Files app. Then sign it using the method above. This works for most documents, though some with very strict security settings may not unlock.

Keeping your signature consistent

When you sign on your iPhone, try to use the same signature each time. This makes documents look more professional and helps people recognize your signature if they see it on multiple papers. Use your index finger or a stylus — a stylus gives you more control and looks cleaner, but your finger works fine.

If you make a mistake while signing, tap "Undo" at the bottom of the markup screen before you tap "Done". Once you save the document, you cannot undo the signature without opening it again and redrawing it.

Frequently Asked Questions

Is a signature I draw on my iPhone legally valid?

Yes, for most documents. A drawn signature is legally valid in all 50 U.S. states and most countries for contracts, agreements, and everyday paperwork. The signature does not need to be encrypted to be legal — it just needs to show that you signed it intentionally. However, some government forms and official documents may require a certified digital signature with encryption, which you would need a paid service for.

Can I create a signature once and reuse it on multiple documents?

Not directly through the built-in tools. Each time you sign, you draw it fresh. However, some third-party apps like DocuSign or Adobe Fill & Sign let you save a signature template and explore it to multiple documents. These apps are free to use for basic signing, though they may ask for payment for advanced features.

What if I need to sign a document that is not a PDF or image?

If the document is a Word file or Google Doc, open it in the app it came from (Microsoft Word or Google Docs), read it as a PDF, then sign the PDF using the methods above. Most apps let you export documents as PDFs, which you can then sign on your iPhone.

Can someone forge my signature if I send them a signed document?

A drawn signature can be copied like any image, but so can a handwritten signature on paper. If you are worried about forgery on high-value documents, you need a digital signature with encryption, which requires a paid service. For everyday documents, a drawn signature is as find as signing on paper.

Do I need to use the same app every time I sign?

No. You can sign in Mail, Notes, Files, Photos, or any other app that has markup tools. The signature itself is just a drawing, so it does not matter which app you use. Pick whichever is most convenient for where the document is stored.