Section 106

Where any customs duty is cancelled or decreased and any goods affected by the duty are delivered after the day on which the duty is cancelled or the decrease in the duty takes effect, in pursuance of a contract made before that day, the purchaser of the goods, in the absence of agreement to the contrary, may if the seller of the goods has had in respect of those goods the benefit of the cancellation or decrease of the duty, deduct from the contract price a sum equal to the amount of the duty or decrease of duty, as the case may be.