Change in rate of tax: time of supply determined by invoice, payment receipt or supply dates, affecting applicable GST rate. Change in rate of tax fixes the time of supply by reference to three events: date of supply, date of invoice and date of receipt of payment; if any two events fall before the rate change the supply is treated as before the change, and if any two fall after it is treated as after the change. Suppliers of goods (other than composition dealers) remain subject to the invoice-time payment procedure; date of receipt is the earlier of bank credit or book entry, with bank credit bearing on timing only if it occurs beyond four working days after the rate change.