How to sign a PDF in Outlook

On Windows

1. 1

   Save the attachment

   In the email, open the attachment's menu and save it to your PC, for example to your Desktop.

2. 2

   Open it in Microsoft Edge

   Right-click the saved PDF and choose Open with, then Microsoft Edge.

3. 3

   Sign with Draw

   Select Draw in the PDF toolbar and sign with your mouse, touchpad or pen. Click into any blank fields to type, then select Save.

4. 4

   Reply with the signed file

   In Outlook, reply to the message and attach the signed PDF. Check you attached the signed copy, not the original.

Prefer Adobe? Free Acrobat Reader's Fill & Sign tool lets you type, draw or insert an image of your signature. See our Windows guide for both methods in detail.

On a Mac

1. 1

   Save the attachment

   Save the PDF from Outlook to your Mac.

2. 2

   Open it in Preview

   Control-click the file, choose Open With, then Preview.

3. 3

   Add your signature

   Click Show Markup Toolbar, then Sign. Create a signature with your trackpad, camera or iPhone, then drag it into place and save.

4. 4

   Attach it to your reply

   Reply in Outlook and attach the signed file.

Full steps, including how to create a signature with your iPhone, are in our Mac guide.

What about Microsoft 365 eSignature?

Microsoft offers an eSignature service for Microsoft 365 organizations. It sends Word documents and PDFs stored in SharePoint for signature, to people inside or outside the company, with an audit trail. It isn't a button in Outlook, though. An admin has to set it up, it's billed pay-as-you-go through an Azure subscription, and outside signers need guest access configured. It's a good fit for a company already deep in SharePoint, and a lot of setup for a small business that just needs a contract signed.

Why replying with attachments gets messy

• Each signer repeats the routine. Save, open another app, sign, attach, reply. Some won't manage it.
• Copies drift. Several "signed" versions end up in different inboxes.
• There's no proof. A signature pasted into a PDF doesn't show who added it, from where, or when.

Send it for signature with SignMaster

SignMaster works next to Outlook without any add-in. Your signers get an email with a link, not an attachment, and they sign in their browser. Each document you send is an envelope: one or more documents going to one or more signers.

1. 1

   Upload the PDF

   Save the attachment, start a new envelope in SignMaster, and upload it.

2. 2

   Add signers and fields

   Enter each signer's name and email, set the order, and place signature, initials, date signed and text fields. Click Add me to include yourself.

3. 3

   Send

   Each signer gets an email saying the document is ready to review and sign. They don't need an account.

4. 4

   Get it back in Outlook

   When the last person signs, everyone receives an email with the signed PDF and its certificate of completion attached.

The certificate lists each signer's email, IP address, device and the time they viewed, consented and signed, which is the record a pasted signature lacks.