Adagio OrderEntry decides the tax rate for each jurisdiction (GST, PST, HST etc) based on a comparison of rates between the customer status and the item status. Whichever rate is lower will be the rate used for each tax jurisdiction.

Tax statuses for customers are stored on the customer master record and also on ship-to addresses. The tax status on the shipping address will always override what is on the customer - it currently cannot be set to blank - so if you want to ensure that the customer master tax status is used, then you must check that the tax status on every shipping address is the same as for the customer master.

As this is a technical support question, this thread will be moved there.