30.This paragraph provides the rules for determining which non-resident parents will have a liability calculated at the reduced rate.
Sub-paragraph (1) provides that a reduced rate is payable where the non-resident parent’s net income is less than £200 but more than £100, unless the non-resident parent is liable for the nil rate or flat rate of liability.
Sub-paragraph (2) provides for the reduced rate (or its method of calculation) to be prescribed in regulations.  The intention is that regulations will provide for percentages to be applied to net income so that liability increases in proportion to the amount by which net income exceeds £100.
Part 1: Child Support. Commentary on Sections Schedule 1: Calculation of weekly amount of child support maintenance Paragraph 3: Reduced rate