When adding a user to your Mercury account, there are several different types of user permissions.

Admin - They have full access to the account and can make changes to teams, cards and can invite others to the account. This is the most high-level account type. 

Bookkeeper - This user will be view-only. They cannot invite team members or move money. This would be best suited for an accountant.

Custom User - There are 3 different options here: Can Move Money with Approval, Can Move Money Without Approval, Cannot Move Money. Custom users can view all accounts but cannot access security settings or manage the team.