If you are a Skype for Business Online user, use Otherwise, use domain\username. Your sign-in address looks like this: might be asked for both a user name and a sign-in address. If you’ve forgotten your password or it’s no longer working, use the Microsoft Online Password Reset site to send a new password request to your workplace technical support-typically the person who set up your Microsoft 365 account for you. For more information, see Sign in to Skype for Business. If you’re already using Skype for Business on your desktop, then you can sign in with the credentials from your work or school account.
You need a sign-in address and password from an organization that has a Skype for Business or Lync license. How do I sign in to Skype for Business on Mac?
