How to Change Your Email Signature in Outlook (Desktop, Web & Mobile)

Your email signature is one of the first things recipients notice — and one of the easiest things to forget to update. Whether you've changed jobs, got a new phone number, or just want a cleaner look, Outlook gives you multiple ways to edit, create, and manage signatures. The exact steps depend on which version of Outlook you're using, and that's where a lot of confusion starts.

Why Outlook Has Multiple Signature Settings

Microsoft Outlook exists across several distinct platforms: the classic desktop app (part of Microsoft 365 or standalone Office), the web app (Outlook.com or the browser-based Microsoft 365 version), and mobile apps for iOS and Android. Each platform manages signatures independently, which means changing your signature in one place does not automatically update it in another.

This catches a lot of people off guard. You edit your signature on your laptop, then send an email from your phone — and the old signature is still there. That's expected behavior, not a bug.

How to Change Your Signature in Outlook Desktop (Windows)

The classic Windows desktop app gives you the most control over signature formatting.

1. Open Outlook and click File in the top-left corner
2. Select Options, then navigate to Mail
3. Click the Signatures… button
4. In the Signatures and Stationery window, select the signature you want to edit from the list
5. Make your changes in the editor below — you can adjust text, add images, change fonts, or insert hyperlinks
6. Use the dropdown menus on the right to assign which signature appears for new messages and which appears for replies/forwards
7. Click OK to save

Key distinction: Outlook desktop lets you set different signatures for new emails versus replies. Many users miss this and end up with a full signature block appended to every reply chain, which can look cluttered.

How to Change Your Signature in Outlook on Mac

The Mac version of Outlook (part of Microsoft 365) handles signatures slightly differently from the Windows version.

1. Open Outlook and go to Outlook in the menu bar, then Settings (or Preferences)
2. Click Signatures
3. Select an existing signature to edit, or click the + button to create a new one
4. Edit the content in the text area on the right
5. Use the dropdowns to assign default signatures per account

The Mac editor is more limited in formatting compared to the Windows version. Rich HTML signatures with complex layouts or images sometimes display differently, depending on how your IT environment is configured.

How to Change Your Signature in Outlook Web App ✉️

If you use Outlook through a browser (either Outlook.com or your organization's Microsoft 365 web portal):

1. Click the Settings gear icon in the top-right corner
2. Search for "signature" in the settings search bar, or navigate to Mail → Compose and reply
3. Find the Email signature section
4. Edit the text directly in the signature editor
5. Toggle options to automatically include the signature on new messages and/or replies
6. Click Save

The web app's signature editor supports basic formatting — bold, italic, links, and images — but has fewer layout options than the desktop app. If your organization uses Exchange or Microsoft 365 Business, your IT admin may also apply server-side signatures, which are appended automatically regardless of what you set here.

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

The Outlook mobile app has its own separate signature settings, and it's intentionally simpler.

1. Tap your profile photo or initials in the top-left corner to open the menu
2. Tap the gear icon to open Settings
3. Scroll down to find Signature
4. Edit the text directly — mobile signatures are plain text only, with no rich formatting support
5. Toggle whether the signature applies to all accounts or just one

Because mobile signatures are plain text, anything formatted with HTML on desktop (logos, styled fonts, color-coded text) won't carry over. Mobile sends a clean text version instead.

Variables That Affect Your Setup 🔧

How your signature behaves depends on more than just which app you're using:

Server-side signatures are worth understanding separately. If your organization manages email through Exchange or Microsoft 365, an IT administrator can apply signatures (or legal disclaimers) automatically on the server level. These override or append to whatever you've set locally — and in some setups, you may not be able to remove them without admin access.

The Spectrum of Signature Complexity

For personal accounts, a simple text signature with your name and contact details takes about two minutes to set up across all platforms.

For business accounts, especially in managed Microsoft 365 environments, the picture is more layered. Organizations sometimes use third-party signature management tools (such as Exclaimer or CodeTwo) that push consistent signatures to all employees regardless of device. In those cases, your local signature settings may be partially or fully overridden.

Individual freelancers and small business users in the middle often manage signatures manually across two or three platforms — which works fine once you understand that each one is a separate configuration.

The right approach to managing your Outlook signature — how many you create, where you assign them, and how much formatting you invest in — depends heavily on how many accounts you manage, which devices you send from, and whether your email environment is personal or organizationally controlled.