Should you need to locate an account without an assigned fee structure, first navigate to the Clients Page. Make sure you're in Accounts View (default)

From there, filter the accounts by fee structure and look for (blanks). This will pull up any accounts with unassigned fee structures. Alternatively, you can hit the Fee Structures column header in order to sort the data.

Should you need to locate accounts that are not assigned a billing group, you will need to first add Billing Group as a column to the table. From there, you can filter or sort as needed.

You can also head to Billing Review mode for an easier method of reviewing billing details for each account.