About digital signatures and certificates in Office, and buying a digital certificate from a certificate authority or create your own.

Signing your email messages with a digital ID helps to prove your identity and prevent message tampering.

Find everything you need to manage your Microsoft account, Xbox profile, and more.

Certificate authority (CA) A certificate authority is an entity similar to a notary public. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Top of Page Digital signature assurances The following terms and definitions show what assurances are provided by digital signatures. Authenticity The signer is ...

See how to view the details for signatures and certificates.

How to create or edit your Outlook signature for email messages. Include your signature, text, images, electronic business card, and logo.

To learn about digital signatures (also known as digital ID), what they can be used for, and how to use them in Word, Excel, and PowerPoint, see All about digital signatures. Create a signature line in Word or Excel (desktop) In the document or worksheet, place your pointer where you want to create a signature line. On the Insert tab, select Add a Signature Line in the Text group. In the ...

Create a custom signature block with a picture and social networking icons to add as a new signature for your email messages.

Learn how you can use the free Microsoft Authenticator app to sign in to all your accounts without using a password.

Automatically add a signature to a message You can create an email signature that you can add automatically to all outgoing messages or add manually to specific ones. Select Settings at the top of the page, then For Outlook.com, select Account > Signatures. For Outlook on the web, select Account > Signatures. Under Email signature, type your signature and use the available formatting options ...