7.—(1) A discounted amount is payable instead of the amount specified in regulations under paragraph 5 if payment is made before the end of the period for payment of the discounted amount.
(2) That period is the period of 15 days beginning with the day on which the notice is given, unless the 15th day is not a working day.
(3) If the 15th day is not a working day, that period is the period beginning with the day on which the notice is given and ending immediately after the first working day following the 15th day.
(4) In this paragraph “working day” means any day which is not a Saturday, Sunday, Christmas Day, Good Friday or a day which is a bank holiday in Northern Ireland under the Banking and Financial Dealings Act 1971 (c. 80).