The fastest way to sign on iPhone

You can sign a Word document on your iPhone using the built-in Markup tools in the Files app or directly within Microsoft Word if you have the app installed. The simplest path is to open the document in Word, tap the Review tab, select Sign, and draw your signature on the screen. If you do not have Word installed, you can use the Files app to mark up the document with your signature instead.

Both methods create a visible signature that appears in the document itself — not a separate digital certificate. This works for documents you need to sign informally, like agreements between people who know each other or internal company forms. For legally binding signatures that need verification, you would need a service like Adobe Sign or DocuSign instead, but those are separate apps.

Key Takeaways

  • Microsoft Word on iPhone has a built-in Sign feature under the Review tab that lets you draw your signature directly into the document.
  • If you do not have Word installed, the Files app can mark up any document with your handwritten signature using Markup tools.
  • Both methods create a visible signature image in the document but do not create a legally verified digital signature.
  • You can resize and reposition your signature after drawing it, and undo it if the placement is wrong.

Signing directly in Microsoft Word

Open the Word document on your iPhone and tap the Review tab at the bottom of the screen. Scroll right through the ribbon menu until you see the Sign button, then tap it. A blank signature box will appear in your document — you can move it to a different location by tapping and dragging before you sign.

Tap inside the signature box and draw your signature with your finger. Take your time — you can draw slowly and the app will capture the motion. Once you finish, tap outside the box to complete the signature. If the signature does not look right, tap the box again and select Change Signature to redraw it. You can also resize the box by dragging the corners.

After you sign, save the document by tapping the filename at the top and selecting Save. The signature is now part of the document and will appear when anyone opens it.

Signing using the Files app and Markup

If you do not have Microsoft Word installed, you can still sign a Word document using the built-in Markup tool. Open the Files app on your iPhone and navigate to the folder where your Word document is stored. Tap and hold the document, then select Quick Actions and tap Markup. The document will open in preview mode.

Tap the Markup button (it looks like a pen in a circle) at the bottom right of the screen. A menu will appear with drawing tools. Select the Signature tool — it usually looks like a pen or signature icon. Draw your signature on the document, then tap Done. The signature will be added as an image overlay on top of the document.

Tap Save to keep the changes. The document will be saved with your signature embedded. Note that this method adds your signature as a visual layer rather than inserting it into the document structure the way Word does, but the result looks the same to anyone who opens the file.

Positioning your signature in the right place

In Word, the signature box appears wherever your cursor was positioned when you tapped Sign. If you need the signature in a specific location — like at the end of a contract or next to a date field — scroll to that spot first, tap to place your cursor there, then open the Sign menu. This saves you from having to move the box afterward.

If you already placed the signature in the wrong spot, tap the signature box and drag it to the correct location. You can also resize it by dragging the corner handles. In the Files app Markup method, you have less control over placement because you are drawing directly on the page, so it helps to scroll to the right section of the document before you start drawing.

What to do if your signature does not look right

In Word, tap the signature box and select Change Signature to erase it and draw a new one. You can do this as many times as you need. If you want to remove the signature entirely, tap the box and press Delete.

In the Files app, if you made a mistake while drawing, tap Undo at the bottom of the Markup screen to erase the last stroke. You can undo multiple times to go back several steps. If the entire signature is wrong, tap the eraser tool and erase the whole signature, then redraw it.

Saving and sharing your signed document

After you sign the document in Word, save it by tapping the filename at the top and selecting Save. The document stays in your OneDrive or local storage with the signature embedded. You can then share it by tapping the Share button (arrow pointing out of a box) and selecting how you want to send it — email, Messages, AirDrop, or another app.

If you signed using Markup in the Files app, the changes are saved to the original file. You can share it the same way: tap and hold the document in Files, select Share, and choose your method. The person who receives the document will see your signature exactly as it appears on your screen.

When you need something stronger than a handwritten signature

A handwritten signature in Word or Markup is visible proof that you signed the document, but it does not verify your identity or prevent the document from being edited afterward. If you need a legally binding signature — one that proves you signed it and that the document has not been changed since — you need a separate service like Adobe Sign, DocuSign, or HelloSign.

These apps create a digital signature that includes encryption and a timestamp, and they track who signed what and when. They are required for contracts, financial documents, and anything that might be challenged in court. For casual use — sharing a draft with a coworker, signing an internal form, or confirming you read something — a handwritten signature in Word is enough.

Frequently Asked Questions

Can I use my saved signature instead of drawing one each time?

In Microsoft Word, the first time you sign a document, the app saves that signature. The next time you tap Sign, it offers to insert the same signature automatically. You can accept it or draw a new one. This saves time if you sign many documents.

Will my signature look the same on someone else's phone?

Yes. Your signature is saved as an image in the document, so it will look identical no matter what device opens the file. The size and position might shift slightly depending on the document layout, but the signature itself does not change.

Can I sign a document that is not in Word format?

You can sign PDFs using the Files app Markup tool, but Word documents are easier because Word has a dedicated Sign feature. If you have a document in another format, convert it to PDF first, then use Markup to add your signature.

What if the document is protected or read-only?

You cannot sign a read-only document in Word. Ask whoever sent it to you to remove the read-only protection, or read a copy you can edit. In the Files app, you may be able to mark up a read-only file, but the changes will be saved as a separate marked-up version.

Does signing on iPhone work the same way as on a computer?

The process is similar but not identical. On a computer, Word has more signature options and you can insert a scanned image of your signature. On iPhone, you draw your signature with your finger, which is faster but less precise. The end result — a visible signature in the document — is the same.