8.—(1) Where the contributions paid by a self-employed person for any relevant year recomputed in accordance with regulation 6 exceed the contributions already paid by him for that year, the self-employed person shall make such amount of additional contributions as is equivalent to the difference to the Fund.
(2) The self-employed person shall contribute the amount of the difference referred to in paragraph (1) within 30 days or such other extended time as the Board may allow after the date of issue of the notice of computation.
(3) Any additional contributions referred to in paragraph (1) may be paid in instalments so long as the total amount of such contributions is paid within the relevant period referred to in paragraph (2).