How to Change Your Signature in Outlook: A Complete Guide

Your email signature is one of the first things recipients notice — and one of the easiest things to get wrong or forget to update. Whether you've changed jobs, updated your phone number, or just want a cleaner look, knowing how to change your signature in Outlook is a practical skill that works slightly differently depending on which version you're using.

Why Outlook Signatures Work the Way They Do

Outlook stores signatures locally on your device (for the desktop app) or in your account settings (for Outlook on the web). This distinction matters more than most people realize. If you update your signature in the Outlook desktop app on your work PC, that change won't automatically appear when you log into Outlook.com from a browser or a different machine. They're managed in separate places.

This is a common source of confusion — and it means you may need to update your signature in more than one location depending on how you access your email.

How to Change Your Signature in Outlook Desktop (Windows)

The desktop app for Windows is what most office users interact with daily. Here's how the process works:

1. Open Outlook and click File in the top-left corner.
2. Select Options, then navigate to Mail.
3. Click the Signatures… button — this opens the Signatures and Stationery dialog.
4. In the "Select signature to edit" box, click the signature you want to modify.
5. Edit the text in the editor below. You can change fonts, add images, insert hyperlinks, or adjust formatting.
6. Under "Choose default signature", confirm which signature is assigned to new messages and replies/forwards.
7. Click OK to save.

One thing worth knowing: the signature editor in the desktop app is fairly basic. For more complex formatting — logos, branded layouts, clickable social icons — many users paste pre-formatted HTML or build the signature externally first.

How to Change Your Signature in Outlook on Mac 🖥️

The Mac version of Outlook has a slightly different path:

1. Open Outlook and go to Outlook in the menu bar, then select Preferences.
2. Click Signatures.
3. Select the signature you want to edit from the left panel.
4. Make your changes in the editor on the right.
5. Close the window — changes save automatically.

The Mac interface is more streamlined than Windows, but offers similar formatting options. If your organization uses a standardized email signature enforced by IT policy, your ability to edit may be restricted at the admin level.

How to Change Your Signature in Outlook on the Web (Outlook.com or Microsoft 365)

For browser-based Outlook — whether through Outlook.com or your company's Microsoft 365 portal:

1. Click the gear icon (Settings) in the upper-right corner.
2. Select View all Outlook settings at the bottom of the panel.
3. Go to Mail → Compose and reply.
4. Find the Email signature section.
5. Edit your signature in the text box provided.
6. Toggle the options to automatically include it in new messages and/or replies.
7. Click Save.

The web editor supports bold, italic, links, and images, though it's more limited than some dedicated HTML editors.

How to Change Your Signature in the Outlook Mobile App 📱

On iOS or Android, Outlook uses a simple plain-text signature by default ("Get Outlook for iOS" is the out-of-the-box default). To change it:

1. Tap your profile icon in the top-left corner.
2. Go to Settings (gear icon).
3. Select your email account under the accounts list.
4. Tap Signature.
5. Clear the existing text and type your new signature.
6. Tap the back arrow — it saves automatically.

Mobile signatures are plain text only in the standard Outlook app. Rich formatting, logos, and HTML are not supported at the mobile level, which is an important limitation for users who need branded signatures on the go.

Key Variables That Affect Your Signature Setup

A Note on Multiple Accounts and Multiple Signatures

If you manage more than one email account through Outlook, each account can — and should — have its own signature. In the desktop app, you assign signatures per account when choosing defaults. Mixing this up is a frequent issue when users add a second account and don't realize their personal signature is being appended to work emails, or vice versa.

You can also create multiple signatures and switch between them manually per email — useful if you have a formal version for external clients and a shorter one for internal messages.

What "Default Signature" Actually Means

Setting a default signature in Outlook controls two separate behaviors: what appears on new messages and what appears on replies and forwards. These can be set independently. Many professionals use their full signature on new emails but a shorter version (or no signature at all) on replies, to avoid cluttered email threads.

Whether that approach fits your communication style, your industry norms, or your company's expectations is something only your specific situation can answer.