Hi Sam,

You should create a Filter for all Customers where the State (Province) is ON and the Tax Type <> 1. Another Filter could list all Customers where the Tax Group <> "CANADA". A third could list all customers where the Province <> "ON" and the Province <> "AB" just to quickly make sure that those are set up correctly. You could also have a Filter that Highlights the Customer in RED if the Tax Group and tax Code do not follow the rules you have defined above.

Filters are great for quickly checking exception conditions.