105.Paragraph 5provides additional regulation-making powers relating to variations.
Sub-paragraphs (1) and (3) provide regulation-making powers relating to the manner in which the Secretary of State may modify the normal rules for calculating maintenance in the event of a successful variation application.  The Secretary of State will normally give effect to a variation by offsetting the expenses against, or increasing the value of, the non-resident parent’s net income prior to any further adjustment in respect of relevant children (where appropriate).  The only exception to the normal rules will apply, as now, to pre-1993 property transfers, where the equivalent weekly value of the transfer (as calculated) will be deducted from the non-resident parent’s “bottom line” liability.
Sub-paragraph (2) provides that no variation may be made other than in the circumstances prescribed.
Sub-paragraphs (4) and (5) provide that the Secretary of State may by regulations impose a limit on the amount of special expenses which he may take into account for the purposes of a variation, and that regulations may provide for different provision with respect  to different levels of income.  The intention is that the Secretary of State will recognise expenditure on certain of the prescribed grounds only in so far as it exceeds £10 or £15 per week, depending on the non-resident parent’s net weekly income.
106.Paragraph 6 provides that the Secretary of State may, by regulations, and with prescribed modifications, apply the “shared care” rules and adjustments referred to in paragraph 7 of Part I, Schedule 1 (as substituted by Schedule 1 to this Act) in cases where he has agreed to a variation of the normal rules by which the maintenance liability is calculated.
Part 1: Child Support. Commentary on Sections Part II: Regulatory controls