Add a professional email signature to your Microsoft 365 email in Outlook on the web, the new Outlook, classic Outlook, Mac and mobile. This guide also explains when a company-wide signature or disclaimer set by an administrator is the better choice.
Before you start
- Keep it short: name, job title, business name, phone number and website. A small logo is fine, but large images often show up as attachments or get blocked.
- If you include a logo, host it as an image on your website or insert a small file (under about 50 KB) rather than a full-size photo.
Outlook on the web and the new Outlook for Windows
- Open Settings (gear icon) → Accounts → Signatures. If you can't find it, search settings for "signature".
- Select New signature (or Add signature), give it a name and type or paste your signature. Use the toolbar to add formatting, links and images.
- Choose default signatures. Under Select default signatures, pick which one to add For New Messages and For Replies/Forwards. Many people use a shorter one for replies.
- Select Save. Start a new email to check it appears.
To add a signature by hand while writing, select Insert → Signature.
Classic Outlook for Windows
- Select File → Options → Mail → Signatures. (Or, in a new message, Message → Signature → Signatures.)
- Select New, name the signature and create it in the edit box.
- Choose default signature. On the right, choose the email account, then the signature for New messages and Replies/forwards.
- Select OK.
Outlook for Mac and mobile
- Outlook for Mac: Outlook → Settings → Signatures, add one with +, then choose defaults per account.
- Outlook for iPhone and Android: tap your profile picture → settings gear → Signature. The mobile app uses its own plain signature (by default "Get Outlook for iOS/Android"), so replace it with yours.
Does my signature follow me between Outlook apps?
For Microsoft 365 work accounts, signatures you create in Outlook on the web and the new Outlook are saved in your mailbox, and recent versions of classic Outlook use these "cloud signatures" too. Older signatures that were created only on one PC may not appear elsewhere. If a signature is missing, recreate it once in Outlook on the web. Phones always need their own signature.
Admins: one signature or disclaimer for everyone
If you want the same footer on every external email (for example your registered company number and address, which UK companies must show on business emails), an administrator can add it centrally with a mail flow rule. It's added on the server, so it works from every device. See Exchange admin: mail flow rules, disclaimers and anti-spam.
Mail flow rules add the text to the end of the whole message thread, not under your personal sign-off, and can't easily personalise per user. For fully designed, personalised signatures across all devices, businesses typically use a third-party signature service.
Troubleshooting
My logo shows as an attachment or a red cross
Some recipients' email programs block or attach embedded images. Use a small image, and avoid copying a signature from a web page or Word document that links to files on your PC.
The signature appears twice
Usually you have a personal signature and an admin-wide disclaimer, or a default signature plus a manually inserted one. Remove one, or ask your administrator to add an exception to the mail flow rule.
The formatting changes when I paste from Word
Paste as plain text and reformat in the signature editor, or build the signature directly in Outlook on the web.
Last reviewed: October 2026
