The fastest way: use the built-in markup tools

The simplest way to sign a document on your iPhone is to use Apple's built-in Markup tool, which works on PDFs and images without downloading anything extra. Open the document in Mail, Messages, Notes, or Files, tap the markup icon (it looks like a pen tip in a circle), select the signature tool, and draw your signature on the screen. Your signature appears on the document immediately.

This method works best when someone sends you a document via email or when you have a PDF saved in your Files app. The signature is added directly to the file, and you can send it back right away. No separate app, no account setup, no waiting.

Key Takeaways

  • Apple's Markup tool lets you sign any PDF or image on your iPhone without installing an app—open the file, tap the pen icon, and draw your signature.
  • If you sign the same documents repeatedly, create a saved signature in Settings > General > Signature so you don't have to draw it each time.
  • For legal or financial documents, check whether the other party accepts digital signatures—some contracts or loan papers require a specific signing method.
  • If Markup doesn't work with your file type, Adobe Acrobat Reader and DocuSign are the most common alternatives, though both require a free or paid account.

Creating a saved signature to use repeatedly

If you sign documents regularly, save your signature once so you can reuse it without drawing it every time. Go to Settings, tap General, then Signature. Tap "Create New Signature," hold your iPhone steady, and sign on the blank screen. Your signature is now saved and will appear as an option whenever you use Markup.

You can create up to three different signatures this way—useful if you sign documents in different contexts (your full legal name for contracts, initials for approvals, a different style for personal use). Each one stays in your phone's settings and syncs across your other Apple devices if you use the same iCloud account.

When to use Adobe Acrobat Reader instead

Markup works for most everyday documents, but some PDFs have form fields or security settings that prevent Markup from working. If you open a PDF and the markup tools are grayed out, try Adobe Acrobat Reader instead. It's free to download from the App Store and handles complex PDFs that Apple's tools cannot.

In Acrobat Reader, open the PDF, tap the pencil icon, then tap "Sign." You can draw your signature, use a saved signature, or type your name. The app also lets you fill in form fields and add dates—useful for official forms that have specific blanks to complete.

Using DocuSign for documents that require it

Some organizations—banks, law firms, HR departments—require you to sign through a specific service like DocuSign. If someone sends you a signing link, tap it and follow the prompts. DocuSign guides you through each step and tells you exactly where to sign. You can draw your signature, upload an image of your signature, or type your name, depending on what the sender allows.

DocuSign keeps a record of when you signed and what you signed, which is why some organizations prefer it for legal documents. You don't need to create an account unless you're the one sending documents for others to sign—receiving and signing documents is free.

What to check before you sign anything

Before you sign any document on your iPhone, make sure you're actually looking at the right file. Zoom in and read the full text, not just the signature line. Check the date, the amount (if it's a financial document), and the names of all parties involved. A signature on the wrong document or a document you didn't read fully can create real problems.

Also confirm that the person or organization sending the document is legitimate. If someone texts you a signing link out of the blue, contact them through a phone number or email you know is theirs—not a number in the message itself. Scammers sometimes send fake signing requests to trick people into authorizing payments or transfers.

Signing documents you receive in email or text

When someone emails you a PDF to sign, open it in Mail, tap and hold the document, then select "Quick Look." Tap the markup icon (pen in a circle) at the bottom, choose the signature tool, and draw your signature. Tap "Done," then tap "Save" to add it to the file. You can then email it back or save it to your Files app.

If someone sends a document via text message, the process is the same—tap and hold the file, open it in Quick Look, and use Markup. Some messaging apps like WhatsApp or Telegram may require you to save the file to your phone first before you can mark it up.

Troubleshooting when signing doesn't work

If the markup tools don't appear or are grayed out, the PDF may have security restrictions set by whoever created it. Try opening the file in Adobe Acrobat Reader instead—it can sometimes bypass restrictions that Apple's Markup cannot. If that doesn't work either, ask the person who sent you the document whether they can remove the restrictions or send it in a different format.

If your signature looks shaky or unclear, make sure you're using a finger or stylus (like an Apple Pencil if you're on an iPad) and that your screen is clean. Practice on a blank note first if you're new to signing on a touchscreen. You can also delete a signature and redraw it as many times as you need before you save the document.

Frequently Asked Questions

Is a signature I draw on my iPhone legally valid?

In most places, yes—digital signatures are legally recognized for contracts and official documents. However, some documents (like a will or a notarized statement) may have specific legal requirements about how they must be signed. If you're signing something important, ask the other party whether they accept digital signatures or need something else.

Can I use a photo of my handwritten signature instead of drawing one?

Yes. In Markup, after you tap the signature tool, look for an option to add an image. You can take a photo of your signature on paper and upload it. This works in Adobe Acrobat Reader too—tap the signature tool and select "Image" to upload a photo of your signature.

What happens if I sign a document by mistake?

If you haven't sent it yet, delete the signature and redraw it or undo the action. If you've already sent it, contact the person who received it and explain the mistake. They may be able to delete it and resend it to you unsigned, or you may need to sign a new version. For important documents, always double-check before you hit send.

Do I need an Apple ID to use Markup?

No. Markup is built into iOS and works without an account. If you want your saved signatures to sync across devices, you need to be signed into iCloud with the same Apple ID on each device, but signing a single document doesn't require it.

Can someone forge my signature if I save it?

A saved signature is just a drawing stored on your phone—it's not a security feature. Anyone with access to your phone could theoretically use it. For highly sensitive documents (like bank transfers or legal contracts), consider drawing your signature fresh each time instead of using a saved one, or ask the organization whether they use additional verification methods.