How to sign a document sent on WhatsApp

On an iPhone

1. 1

   Save the PDF to Files

   Tap the document in the chat to open it, tap the share button and choose Save to Files. Pick a folder you'll find again, like Downloads in iCloud Drive.

2. 2

   Sign it with Markup

   Open it in the Files app, tap Add, then Add Signature, and sign with your finger. Drag the signature onto the line. Our iPhone signing guide covers filling in the form fields too.

3. 3

   Send the signed copy back

   In the WhatsApp chat, tap the attach button, choose Document, and pick the signed file from Files. Tap send. WhatsApp sends documents up to 2 GB, so a long PDF isn't a problem.

On an Android phone

1. 1

   Download and open it

   Tap the document in the chat to download it, then open it with a PDF app such as Google Drive or Adobe Acrobat Reader. WhatsApp also keeps received documents in its WhatsApp Documents folder, which any file manager can open.

2. 2

   Sign it in that app

   In Acrobat Reader, use Fill & Sign. In Google Drive's PDF viewer, use the annotate pen. Signing a PDF on Android walks through both. Save the result.

3. 3

   Attach it in WhatsApp

   In the chat, tap the attach button, choose Document and select the saved file, or share it from the PDF app and choose WhatsApp. The file has to be saved on the phone for WhatsApp to find it.

Signing on paper instead

If you'd rather sign a printed copy in ink, WhatsApp can scan it for you: in the chat's attachment options, choose Scan document, photograph the page, crop it and send. The other person receives a PDF rather than a crooked photo.

If you're the one sending it

Sending a PDF and waiting for a signed copy to come back works, but it leaves you with a picture of a signature, several versions in a chat and no record of who signed. A signing link is cleaner, and you can still deliver it on WhatsApp:

• Send it as a SignMaster envelope. Upload the PDF, add the person's name and email and place their signature field. SignMaster emails them the link, and you can Copy link from the envelope and paste it into the WhatsApp chat too.
• They tap and sign in the browser. Nothing to save, open or attach. They sign on the phone they're already holding, without an account.
• Everyone gets the finished copy. The signed PDF comes back by email with a certificate of completion, so nobody has to dig through a chat for it.
• For many people at once, such as a team or a class, a public signing link works as one link for everyone, with a QR code you can print.