The trade-in rules for the state are not changed by the new taxes going into effect. Like-item trades are taken off the selling price before tax is calculated.
However, because of the new luxury taxes being introduced, it is necessary to process trade-ins differently.
Buy/Trade for Like Merchandise
If you are taking a buy/trade that is being applied to a like-item purchase, you must click the drop-down arrow next to Sales Tax and check the Tax entire sale as if it was one single item checkbox. Multiple trades can be taken against one or more like-item purchases so long as all items involved are of like characteristics.
This sale MUST be limited to the trade-in transaction; you cannot mix other types of transactions on this sale.
Buy/Trade for Non-Like Merchandise
If you are taking a buy/trade that is being applied to one or more non-like item purchases, you should uncheck the Pre-Tax option on each trade-in sale line.