Value of supply: transaction value governs taxable supply with specified inclusions, exclusions and related party rules. Value of supply is the transaction value-the price actually paid or payable where parties are not related and price is sole consideration. Value includes separately charged non GST taxes, amounts supplier is liable for but paid by recipient, incidental expenses (commission, packing), supplier charges at or before delivery, interest/late fees, and subsidies directly linked to price. Discounts are excluded if invoiced at or before supply or if post supply discounts are under agreement and input tax credit attributable to them is reversed. Where transaction value cannot be determined, prescribed methods or notified rules apply. 'Related persons' are expressly defined.