How to Change the Signature in Outlook: A Complete Guide

Email signatures do more than sign off a message — they carry your name, title, contact details, and sometimes your brand. Knowing how to update yours in Outlook is one of those tasks that sounds simple until you're staring at a menu that looks slightly different from every tutorial you've found. Here's what's actually happening under the hood, and what affects how the process works for you.

What Is an Outlook Signature?

An Outlook email signature is a block of text (and optionally images, links, or formatted HTML) that gets automatically appended to your emails. You can configure separate signatures for:

• New messages you compose
• Replies and forwards
• Specific email accounts, if you manage more than one through Outlook

Outlook stores signatures locally on your device (in the desktop app) or in the cloud (in Outlook on the web). This distinction matters more than most people realize.

The Core Variable: Which Version of Outlook Are You Using?

This is the single biggest factor that changes the steps involved. Microsoft has multiple versions of Outlook in active use simultaneously, and the signature settings live in different places in each.

The Classic Outlook desktop app has been the standard for years in corporate environments. The New Outlook is Microsoft's rebuilt version — it looks and behaves more like the web app, and if you've recently updated Windows, you may have been switched over without realizing it.

How to Change Your Signature in Classic Outlook for Windows ✉️

1. Open Outlook and click File in the top-left corner
2. Select Options, then click Mail in the left panel
3. Click the Signatures... button
4. In the Signatures and Stationery dialog, select the signature you want to edit from the list — or click New to create one
5. Edit the content in the text editor at the bottom
6. Use the dropdowns on the right to assign your signature to New messages and/or Replies/Forwards
7. Click OK to save

The editor supports basic formatting: bold, italic, font size, color, hyperlinks, and image insertion. For more complex HTML signatures (with custom layouts or logos), you can paste pre-built HTML directly into the editor, though formatting fidelity varies.

How to Change Your Signature in New Outlook or Outlook on the Web

The process is nearly identical between these two:

1. Click the gear icon (Settings) in the upper right
2. Search for "signature" in the settings search bar, or navigate to Accounts → Signatures
3. Select an existing signature to edit, or click New signature
4. Make your changes using the built-in rich text editor
5. Use the dropdowns to set it as default for new messages or replies
6. Click Save

One notable difference: signatures in the web and New Outlook versions are stored in your Microsoft account's cloud settings, not on your local machine. This means they follow you across devices — but it also means they're separate from any signatures you've set up in the Classic desktop app.

How to Change Your Signature in Outlook for Mac

1. Open Outlook and go to Outlook in the menu bar → Settings (or Preferences in older versions)
2. Click Signatures
3. Select the account you want to edit a signature for
4. Click the + button to add a new one, or click an existing signature to edit it
5. Set defaults for new messages and replies using the dropdowns

Mac versions also support rich formatting and image insertion. If you're using a Microsoft 365 subscription, your Mac version updates frequently, so menu labels may shift slightly between releases.

How to Change Your Signature in Outlook Mobile

On iOS or Android:

1. Open the Outlook app and tap your profile picture or initials in the top left
2. Tap the gear icon to open Settings
3. Scroll to your account and tap Signature
4. Type your new signature and save

Mobile signatures are plain text only — no formatting, no images, no HTML. They're also per-account, which is useful if you manage both a work and personal inbox through the same app.

Factors That Affect Your Setup 🔧

Organizational policies can restrict signature editing in corporate environments. If you're on a work account managed by IT, your company may enforce a signature template through Exchange or Microsoft 365 admin rules — meaning your manual changes get overridden.

HTML signatures behave differently depending on the recipient's email client. A beautifully formatted signature in Outlook may render differently in Gmail or Apple Mail. If consistency matters, simpler is usually more reliable.

Multiple accounts add another layer. Each account in Outlook can have its own signature, and forgetting to set defaults per account is a common reason why signatures disappear from certain outgoing emails.

Image hosting is worth considering if your signature includes a logo. Embedded images can inflate email size and get stripped by security filters; externally hosted images load only when the recipient allows remote content.

Whether you're tweaking a personal sign-off or rebuilding a professional signature from scratch, the right approach depends on which version of Outlook you're running, how your account is managed, and where you need that signature to appear — the desktop, the web, or your phone.