If you have access to more than one account you can connect them together and only use one login.
You need to:
- Get an invite from all different accounts.
- Log in with your existing details to accept the invitation you got via email.
When you accept the invitation you will see a button in the upper left corner with the name of the company you are working with at the moment.
Click on that button and you will be able to change to one of your other accounts.