Yes. If you need to upgrade, you can transition your account to one of the Office 365 Enterprise plans, which are in the same service family as Exchange Online standalone plans. If you want to move to a different service family, for example to a Small Business or Midsize plan, you must first cancel your Exchange Online account and then sign up for a different one. Learn more about upgrading Office 365 plans.
Note that when you upgrade your account, your domain name is transferred to your new account, regardless of whether you brought your own domain name to the account or you set up a domain name when creating your Exchange Online account.