123.—(1) Subject to paragraph (2), the number of weeks over which a payment other than a periodical payment is to be taken into account is to be equal to the number (and any fraction is to be treated as a corresponding fraction of a week) obtained by dividing that payment by the aggregate of £2 and the amount of an income-related allowance which would be payable had the payment not been made.
(2) Where a liable relative makes a periodical payment and any other payment concurrently and the weekly amount of that periodical payment, as calculated in accordance with regulation 124 (calculation of the weekly amount of a liable relative payment), is less than the aggregate of £2 and the amount of an income-related allowance which would be payable had the payments not been made that other payment, subject to paragraph (3), is to be taken into account over a period of such number of weeks as is equal to the number obtained (and any fraction is to be treated as a corresponding fraction of a week) by dividing that payment by an amount equal to the extent of the difference between the amount as calculated under this paragraph and the weekly amount of the periodical payment.
(3) If—
(a)the liable relative ceases to make periodical payments, the balance (if any) of the other payment is to be taken into account over the number of weeks equal to the number (and any fraction is to be treated as a corresponding fraction of a week) obtained by dividing that balance by the amount referred to in paragraph (1);
(b)the amount of any subsequent periodical payment varies, the balance (if any) of the other payment is to be taken into account over a period of such number of weeks as is equal to the number obtained (and any fraction is to be treated as a corresponding fraction of a week) by dividing that balance by an amount equal to the extent of the difference between the amount referred to in paragraph (2) and the weekly amount of the subsequent periodical payment.
(4) The period under paragraph (1) or (2) is to begin on the date on which the payment is treated as paid under regulation 125 (date on which a liable relative payment is to be treated as paid) and under paragraph (3) is to begin on the first day of the benefit week in which the cessation or variation of the periodical payment occurred.