How to sign a PDF in Apple Mail

On a Mac

Markup in Mail on Mac edits images and PDFs attached to a message you're composing. These steps follow Apple's Mail User Guide; menu names shift a little between macOS versions.

1. 1

   Bring the PDF into your reply

   Open the email and click Reply. Turn on including the original attachments: look under the Attach button in the reply's toolbar, or in the Edit menu, where it's called Include Original Attachments in Reply on many versions. Or click Forward and address it back to the sender.

2. 2

   Open Markup on the attachment

   Move the pointer over the PDF in your message. Click the Action pop-up menu that appears at its upper-right corner and choose Markup.

3. 3

   Sign

   Click the Sign tool. Pick a saved signature, or create one with the trackpad, the Mac's camera or a nearby iPhone or iPad. Drag it onto the line and resize it with the blue handles.

4. 4

   Click Done and send

   Click Done, add a line saying the signed copy is attached, and send. Once sent, the markup becomes part of the PDF and nobody can edit it.

Need the signature twice, say on the last page and an addendum? Hold the Option key while you drag a placed signature to make a copy, and use the yellow guides to line it up.

On iPhone or iPad

1. 1

   Open the attachment

   In Mail, tap the PDF in the message to open it.

2. 2

   Tap Markup

   Tap the Markup button, then Add (the plus) and Add Signature. Sign with your finger, or Apple Pencil on iPad, and tap Done.

3. 3

   Place it

   Drag the signature onto the line and resize it with the blue dots.

4. 4

   Reply with the marked-up file

   Tap Done. Mail offers to reply to the sender with the signed PDF attached, start a new message, or save it to Files.

The trouble with signing by reply

Markup is a good fit for a form a school or landlord sends you. It's a weaker fit for a business that sends agreements out: each client has to know these steps, the signed copy comes back as one attachment among many, and nothing records when or from where they signed.

Send for signature from your Mac instead

With SignMaster, your client gets an email with a button rather than an attachment, taps it and signs in Safari or any browser. Each send is an envelope: one or more documents going to one or more signers.

1. 1

   Save the PDF out of Mail

   Drag the attachment from Mail to your desktop, or save it to Downloads.

2. 2

   Start an envelope

   In SignMaster, click New envelope, upload the PDF, and add each signer's name and email. Click Add me if you sign too.

3. 3

   Place fields and send

   Put signature, initials and date signed fields where each person signs, then send. Reminders go out on the schedule you pick.

4. 4

   Get the signed copy

   When the last person signs, everyone's inbox, Apple Mail included, receives the signed PDF with its certificate of completion.