How to Create a Signature in Outlook (Desktop, Web & Mobile)

An email signature does more than sign off a message — it communicates professionalism, provides contact details at a glance, and ensures consistency across every email you send. Outlook gives you several ways to create, customize, and automatically apply signatures, but the exact steps depend on which version you're using and how your account is configured.

What an Outlook Signature Actually Is

In Outlook, a signature is a block of text (and optionally images or links) that can be automatically appended to new emails, replies, or forwards. You can create multiple signatures — for example, a full signature for new messages and a shorter one for replies — and assign them per account if you manage more than one.

Signatures support plain text, rich text, and HTML formatting, meaning you can include styled fonts, logos, social media links, or legal disclaimers depending on what Outlook version you're running.

Creating a Signature in Outlook Desktop (Windows)

This applies to Outlook for Microsoft 365, Outlook 2021, 2019, and 2016.

1. Open Outlook and go to File → Options
2. Select Mail from the left panel
3. Click Signatures… under the "Compose messages" section
4. In the Signatures and Stationery window, click New
5. Give your signature a name (e.g., "Work — Full" or "Personal")
6. Type and format your signature in the editor below — you can change fonts, add links, and insert images
7. Under Choose default signature, assign it to an email account and set when it appears: New messages and/or Replies/forwards
8. Click OK to save

💡 The formatting editor here is basic but functional. For more complex HTML signatures (with logos or branded layouts), some users paste pre-built HTML directly, though the desktop editor doesn't expose raw HTML by default.

Creating a Signature in Outlook on the Web (OWA)

Outlook Web App (accessed via outlook.live.com or your organization's Microsoft 365 portal) has its own signature settings — separate from the desktop app.

1. Click the Settings gear icon (top right)
2. Select View all Outlook settings at the bottom of the panel
3. Go to Mail → Compose and reply
4. Under Email signature, type and format your signature
5. Toggle on Automatically include my signature on new messages and/or replies if desired
6. Click Save

Note: Changes made here won't sync back to the Outlook desktop app. The two environments maintain independent signature settings.

Creating a Signature in Outlook for Mac

The process on Mac differs slightly from Windows:

1. Open Outlook for Mac and go to Outlook → Preferences → Signatures
2. Click the + button to add a new signature
3. Name it and edit the content in the right panel
4. Close the preferences window — it saves automatically
5. To set a default, go back into the signature settings and assign it per account

Mac versions of Outlook have historically had fewer formatting options in the signature editor compared to Windows, particularly around inserting images inline.

Creating a Signature in the Outlook Mobile App 📱

On iOS and Android, Outlook includes a simple signature setting:

1. Tap your profile icon (top left)
2. Go to Settings → Signature
3. Toggle the signature on and type your text
4. Optionally disable "Get Outlook for iOS/Android" if you don't want that default line included

Mobile signatures are plain text only — no rich formatting, images, or HTML. If your workflow depends on a branded signature appearing on mobile-sent emails, some organizations handle this at the server level through Exchange or Microsoft 365 transport rules rather than relying on the mobile app.

Key Variables That Affect Your Signature Setup

The right approach isn't the same for everyone. Several factors shape what's possible and what makes sense:

When Signatures Don't Appear as Expected

A few common causes worth knowing:

• Replies vs. new messages: Outlook lets you set different signatures (or none) for replies. If your signature isn't appearing on replies, check the default assignment in signature settings.
• HTML rendering: Recipients using plain-text email clients may see your HTML signature as raw code or stripped formatting.
• Syncing misconceptions: Many users set a signature in the web app and assume it applies everywhere — it doesn't. Desktop and web are independent.
• Admin-controlled signatures: In corporate environments, your IT department may append a legal disclaimer or company signature at the mail server level. This happens after the email leaves your client, so you won't see it in your sent items.

The Spectrum of Signature Complexity

At the simple end: a name, title, and phone number formatted in plain text. At the complex end: a branded HTML template with a company logo, social icons, legal disclaimers, and a calendar booking link — maintained centrally by an IT team across an entire organization.

Where your needs fall on that spectrum depends on whether you're setting this up for personal use, a small business, or inside a larger organization with brand standards and compliance requirements. The technical steps above are consistent, but what you build inside that signature editor — and which version of Outlook you're building it in — will look very different depending on your situation.