How to Change Your Signature in Outlook: Desktop, Web, and Mobile

Email signatures do more than sign off a message — they carry your contact details, job title, legal disclaimers, or brand identity with every send. Outlook gives you several ways to create, edit, and assign signatures, but the exact steps vary depending on which version of Outlook you're using and how your account is configured.

Why Outlook Has Multiple Signature Systems

Outlook isn't one product — it's a family of apps that share a name but behave differently under the hood. Outlook for Windows (classic desktop), Outlook for Mac, Outlook on the web (OWA), and the New Outlook app each manage signatures through separate settings menus. Signatures created in one version don't automatically sync to another, which catches a lot of users off guard.

This matters because many people access the same email account from multiple devices. A signature you set up in the desktop app won't appear when you send from a browser, unless you configure it there too.

How to Change Your Signature in Outlook for Windows (Classic Desktop)

This is the version most commonly found in corporate and Microsoft 365 environments.

1. Open Outlook and click File in the top-left corner.
2. Select Options, then choose Mail from the left panel.
3. Click the Signatures… button under the "Compose messages" section.
4. In the Signatures and Stationery dialog, select the signature you want to edit from the list on the left.
5. Make your changes in the editing box below — you can format text, insert images, and add hyperlinks.
6. Under Choose default signature, assign which signature appears for New messages and which appears for Replies/forwards.
7. Click OK to save.

Key detail: If you manage multiple email accounts in Outlook, you can set different default signatures for each account separately using the "Email account" dropdown in that same dialog.

How to Change Your Signature in Outlook on the Web (OWA)

If you use Outlook through a browser at outlook.office.com or outlook.live.com:

1. Click the gear icon (Settings) in the top-right corner.
2. Select View all Outlook settings at the bottom of the panel.
3. Navigate to Mail → Compose and reply.
4. Scroll to the Email signature section.
5. Edit your signature in the text box. Use the formatting toolbar to adjust fonts, add links, or insert images.
6. Toggle Automatically include my signature on new messages and Automatically include my signature on messages I forward or reply to based on your preference.
7. Click Save.

Changes here only apply to the web version of your account — not the desktop app.

How to Change Your Signature in New Outlook (Windows)

Microsoft has been rolling out a redesigned New Outlook app that more closely mirrors the web experience. Its signature settings are nearly identical to OWA:

1. Click Settings (gear icon) in the top-right.
2. Go to Accounts → Signatures.
3. Select an existing signature to edit or create a new one.
4. Assign it to the relevant email account and choose when it auto-inserts.
5. Save your changes.

How to Change Your Signature in Outlook for Mac

1. Open Outlook and go to Outlook in the menu bar, then select Settings (or Preferences on older versions).
2. Click Signatures.
3. Select the signature you want to modify, or click + to create a new one.
4. Edit the content in the right-hand panel.
5. Use the dropdown menus to assign default signatures to specific accounts and message types.

The Mac version supports rich formatting but has historically had more limited HTML signature support compared to the Windows desktop app.

How to Change Your Signature in Outlook Mobile (iOS and Android)

The Outlook mobile app handles signatures differently — it uses a plain-text signature only by default, with no rich formatting or images.

1. Open the Outlook app and tap your profile icon in the top-left.
2. Tap the gear icon (Settings) at the bottom-left.
3. Scroll to Mail and select Signature.
4. Edit the text and tap the back arrow to save automatically.

📱 You can set different signatures for each email account added to the app. Tap the account name to switch between them in the signature settings.

Factors That Affect How Signatures Behave

When Signatures Don't Appear as Expected

A few common situations that create confusion:

• Replying in plain text mode strips formatting from HTML signatures — the text appears but images and styling are lost.
• IT-managed or server-side signatures (common in enterprise environments) may be appended after the message is sent, meaning they won't show in your compose window at all.
• Switching from classic to New Outlook resets signature settings — you'll need to recreate them in the new interface.
• Images in signatures sometimes show as broken links for recipients if the image is embedded differently across versions or if the recipient's email client blocks external images.

The Variable That Changes Everything

How you change your signature in Outlook is straightforward once you know which version you're working in — but which settings actually stick, which accounts they apply to, and whether you have the freedom to customize at all depends heavily on your specific setup. A personal Outlook.com account gives you full control. A corporate Microsoft 365 account might have IT policies that override, append, or lock certain signature behavior entirely. The right approach for your situation lives at the intersection of your Outlook version, your account type, and what your organization (or lack of one) allows.