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

Your email signature is often the first professional detail recipients notice after your name. Whether you're updating a job title, adding a phone number, or starting fresh with a new design, editing your signature in Outlook is straightforward — once you know where to look. The catch is that Outlook exists across several platforms, and the steps differ meaningfully depending on which version you're using.

Why Outlook Signatures Can Be Confusing to Edit

Microsoft offers Outlook in multiple forms: the classic desktop app (part of Microsoft 365 or a standalone Office license), Outlook on the web (accessed through a browser at outlook.com or your organization's portal), and the Outlook mobile app for iOS and Android. Each manages signatures independently, meaning a signature you set up in the desktop app won't automatically appear when you reply from your phone or browser.

This is one of the most common points of confusion. If you've updated your signature and it's still showing the old one somewhere, chances are you're working in a different Outlook environment than you think.

How to Edit Your Signature in Outlook Desktop (Windows)

The desktop app gives you the most control over formatting, including fonts, colors, images, and hyperlinks.

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 — this opens the Signatures and Stationery window.
4. In the "Select signature to edit" box, choose the signature you want to modify (or click New to create one).
5. Edit the content in the text editor below. You can format text, insert a logo or headshot image, and add hyperlinks.
6. Under "Choose default signature", select which email account and scenario (new messages vs. replies/forwards) should use this signature.
7. Click OK to save.

✏️ One important note: changes here apply only to new emails you compose going forward. Drafts already open won't update automatically.

How to Edit Your Signature in Outlook for Mac

The Mac desktop app follows a slightly different path:

1. Open Outlook, then go to Outlook in the menu bar and select Preferences.
2. Click Signatures.
3. Select an existing signature to edit, or click the + button to add a new one.
4. Edit the text and formatting in the right-hand panel.
5. Use the Default Signatures section to assign which signature appears for each account.

Formatting options on Mac are somewhat more limited compared to Windows, particularly around image sizing and HTML rendering.

How to Edit Your Signature in Outlook on the Web

If you use Outlook through a browser (common in business environments using Microsoft 365):

1. Click the Settings gear icon 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. Basic formatting tools are available.
6. Toggle on "Automatically include my signature on new messages" and/or replies if desired.
7. Click Save.

Web signatures are stored separately from desktop signatures and only apply when composing email in the browser.

How to Edit Your Signature in the Outlook Mobile App

On mobile, signature options are more basic — typically plain text only, without rich formatting:

1. Open the Outlook app and tap your profile icon in the top-left.
2. Tap the Settings gear at the bottom.
3. Scroll to find Signature (under your account settings).
4. Tap it and edit the text field.
5. Tap the checkmark or back arrow to save.

Some versions of the mobile app allow per-account signatures; others show a single global signature field. This depends on your app version and whether you're on iOS or Android.

Key Variables That Affect Your Experience

When Your Signature Isn't Updating As Expected

A few common reasons edits don't appear to take effect:

• You edited in one Outlook environment but are sending from another. Each platform needs to be updated separately.
• Your organization uses centrally managed signatures. These are applied server-side by an admin and override anything you set locally.
• You're replying to an old email thread where the signature was already inserted before your edit.
• The signature isn't assigned to that specific account or message type (new vs. reply).

The Spectrum of Signature Complexity

What you can practically do with your signature varies quite a bit:

• Simple text signatures (name, title, phone) work reliably across all platforms and render consistently in most email clients.
• Formatted signatures with logos, colors, and hyperlinks work well in the Windows desktop app and web versions but may not render correctly in all recipients' email clients, particularly older or plain-text environments.
• HTML signatures offer the most design flexibility but require either manual HTML editing or a third-party signature generator tool — and still depend on how the recipient's email client handles HTML.
• Company-wide signatures managed through services like Microsoft Exchange or third-party tools are applied outside any individual's Outlook settings entirely.

How much control you actually have — and how polished a result you can achieve — comes down to your specific version of Outlook, your account type, and what your organization's email infrastructure allows. 🔍