If the "admin" doesn't need access to the data do we still have to pay for a license for him?

Hi Mike,

Welcome to Box Community and glad to assist!

Each existing user on a Business account will require license/seat. 

Meanwhile, If you deem the account will not be as useful, you can change your Box Admin and delete the user. 

For more, you can visit the following articles: 

• Transferring Admin Privileges to Another User
• Deleting Managed Users

Thanks for posting!