Transaction value governs customs valuation, with mandatory additions, related-party checks, exchange-rate rules, and notified tariff values. Valuation of imported and export goods for customs purposes is based on the transaction value, meaning the price actually paid or payable at the time and place of importation or exportation, where the buyer and seller are not related and price is the sole consideration, subject to rules. For imported goods, the transaction value includes specified additions such as commissions, brokerage, engineering and design charges, royalties and licence fees, transport, insurance, and handling charges. The Board may notify tariff values for classes of goods, and duty is then chargeable with reference to those values.