There are 4 types of member roles within a company's account.
You can manage members navigating to 'Account' then 'My Account' from the left navigation menu. Select 'Manage members' from the sub-menu.
There is no limit to the number of users within each role.
The rights for each role is defined as follows: -
View payments - View payments made by all company members
Create payments - View payments by all company members and create payments
Approve payments - View payments by all company members, create and approve payments
Admin - All of the above, and manage roles of the team
The first person from a company who signs up for a CardUp account will be an Admin by default.