In addition to general Individual access levels, you can turn on access to billing for any Individual. You may also find it helpful to add your accountant for billing notifications. Billing access includes the ability to view invoices, make payments, and adjust payment preferences.
Separate from billing access, you can customize the notification preference of who should be contacted with billing notices. Turn on billing notices to copy individuals on invoices, payments, and other accounts payable activity.
See the How to edit user access article for step-by-step instructions to update billing access for Users on your account.