How to Change Your Outlook Signature (Desktop, Web, and Mobile)

Your Outlook signature is one of those small details that shows up in every email you send — so knowing how to create, edit, or switch it is genuinely useful. The process varies more than most people expect, because which version of Outlook you're using changes almost everything about where the setting lives and what it can do.

What an Outlook Signature Actually Is

An Outlook signature is a block of text (and optionally images, links, or formatted HTML) that gets appended automatically — or manually — to your outgoing emails. You can set different signatures for new messages versus replies and forwards, and you can have multiple signatures saved and choose between them per email.

Signatures are stored locally in the desktop app, or tied to your account in the web version — which means changes in one place don't always sync to the other.

The Three Versions of Outlook You Might Be Using

This is the most important variable to understand before you start clicking around:

Knowing which one you're in prevents a lot of confusion.

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

This is the version most people picture — the full desktop app installed on a Windows PC.

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
4. In the Signatures and Stationery window, select an existing signature to edit it — or click New to create one
5. Use the editor to format your text, add images, insert hyperlinks, or paste in HTML
6. Under Choose default signature, set which email account uses it and whether it applies to New Messages and/or Replies/Forwards
7. Click OK to save

The editor here supports rich text formatting — fonts, colors, images, and linked logos are all fair game. If you need more precise formatting, some users paste in pre-built HTML directly, though the editor doesn't expose raw HTML by default.

How to Change Your Signature in Outlook on the Web

If you access Outlook through a browser — either through Microsoft 365 at outlook.office.com or a personal account at outlook.live.com — the steps are slightly different:

1. Click the Settings gear icon (top-right corner)
2. Select View all Outlook settings at the bottom of the panel
3. Go to Mail → Compose and reply
4. Scroll down to the Email signature section
5. Edit your signature in the text box — formatting tools are available in the toolbar above it
6. Toggle options for automatically including the signature on new messages and/or replies
7. Click Save

Changes here are account-based, meaning they follow you across devices when you log into the web version.

How to Change Your Signature in New Outlook (Windows)

Microsoft is gradually replacing Classic Outlook with a redesigned app. If you're on the newer version:

1. Click the Settings gear in the top-right
2. Select Accounts → Signatures
3. Edit an existing signature or create a new one
4. Assign it as the default for new emails or replies

Because New Outlook shares its backend with the web version, signatures here sync with Outlook on the Web automatically.

Outlook Mobile: What's Different 📱

The iOS and Android Outlook apps handle signatures separately from the desktop or web versions. Mobile signatures are typically plain text only — no rich formatting, no images.

To change it:

• Tap your profile icon → Settings
• Scroll to Signature
• Edit the text and save

If you're used to a nicely formatted desktop signature with a logo and styled fonts, expect that the mobile version will be a stripped-down alternative. They don't sync to each other.

Common Variables That Affect Your Setup

A few factors that influence what your signature experience actually looks like:

• Microsoft 365 vs. personal account — Business accounts managed by an IT department may have organization-level signatures applied server-side, which can override or append to personal ones
• HTML vs. plain text — If recipients have email clients set to plain text, even a beautifully formatted signature will arrive as stripped text
• Image hosting — Images embedded directly in a signature can increase email file size and sometimes trigger spam filters; linked images display cleanly but require an internet connection to load
• Multiple email accounts — Classic Outlook lets you assign different default signatures per account, which matters if you manage both personal and work inboxes in the same app

When Signatures Don't Appear as Expected 🔍

A signature that works perfectly on your end can look broken or missing on the other side for a few reasons:

• The recipient's email client strips HTML formatting
• Your IT admin has applied a server-side signature that conflicts with your personal one
• You're replying from a mobile device that has a separate (or empty) signature setting
• The email was sent from a shared mailbox or alias with its own signature configuration

Understanding which Outlook environment you're working in, and what your recipient's setup looks like, shapes how much control you actually have over the final result — and that's a combination only your specific situation can answer.