Recomputation of contributions
6.—(1)  When the notice of assessment in respect of the income derived or received by a self-employed person in any relevant year is subsequently issued by the Comptroller after the end of the relevant year, the amount of contributions payable by the person shall be recomputed on the basis of the amount of income stated in that assessment.
(2)  Where a self-employed person’s income in any relevant year is not stated in a notice of assessment because his income is not chargeable to tax, the amount of contributions payable for that year may be recomputed on the basis of the amount of income assessed by the Comptroller and stated in the notice of computation.
(3)  Where the notice of assessment in respect of income of a self-employed person for any relevant year is amended or varied on appeal or where a notice of additional assessment has been issued by the Comptroller, the amount of contributions payable by him for that year shall be recomputed by taking into account the amount of income which has been varied or added.
(4)  Paragraphs (1) and (2) shall not apply to contributions payable by a self-employed person for the relevant year beginning 1st January 2002 and any subsequent relevant year.