When selling a property, a key question arises regarding the deductibility of Goods and Services Tax (GST) on brokerage fees for capital gains tax calculations. The consensus is that the total amount paid, including GST, should be considered as the expense incurred for the sale. This means if you paid £106,200 including £16,200 GST on a £90,000 brokerage fee, you should claim the full £106,200 as an expense. It's also advised to make such payments via cheque rather than cash for proper record-keeping.