Yes you can!
If you want to create another account, go to Companies in the top bar and click on 'Create new company':
You will be directed to the account creation screen.
Your email address can also be invited as owner/user for multiple accounts. This needs to be done by another user with owner access (i.e. the email address that created the account). For more information on user roles and the invitation process, see this article.
Note: User access applies to the entire account. If you have an agency account you cannot give one of your customers access to only one project for example. If you want to give your customers access as an agency or the customer asks for this, you need to create separate accounts for them. When this separate account is created, you can contact us to move the project of the customer to this new account. The customer can give you, as agency, access to this new account.