After each
Rate & Boundary Import. The import process deletes
Tax Schedules that are no longer valid, but does not remove those schedules from the address records. The Assign Tax Schedules routine updates address records with the proper tax schedule IDs. When a state creates a new tax or drops an old tax, any customer addresses that are subject to the effected tax jurisdiction(s) must also be updated. These are the kind of reasons why you must run the Assign Tax Schedules routine after every import.