You can share an account with team members.

To add team members to your account, click on "Your Account" at the top right, then "Account Settings". On Account Settings, click on "My Team"

Then enter the email address of the team member you want to add and click on "Invite member". 

All invited users are "Members" by default, once they accept the invite. 

Members can only use the tools available to their company account; they cannot invite other people or manage billing. If you want them to be able to manage billing and integrations (e.g., add email addresses to your SMTP set-up), you would need to change their access to "Admin"

Admins can use the tools, manage members (add or remove members), and manage integrations. Admins cannot manage billing (subscribe, cancel, change payment method, etc.); only Super Admins can, and there can be only one Super Admin on an account.

To change the role from member to admin or another role, click the three dots next to the member and select "Change permission". Then select the new role and save the changes.

Removing a member is similar; click on the three dots, select "Remove member", and confirm you want to remove that member.