Sales return timing determines whether GST applies; returns after the prescribed period attract GST, within period may be exempt. Where goods sold under the earlier law are returned after the GST appointed day, tax liability depends on whether the goods are taxable under GST and whether the return occurs after the prescribed six month transitional period; if both are met, GST is payable. Returns within the six month period are not taxable if the goods are identifiable and tax was paid under the earlier law at the time of sale, provided that sale was made not earlier than six months before the appointed day; see section 149.