61.There will be circumstances in which a final maintenance calculation cannot be made straightaway, for example, when sufficient details are not made available, or need to be verified. The reformed scheme will allow for maintenance to be collected:
	where the information needed to complete a maintenance calculation (apart from information needed in relation to a variation application) is not immediately available, using a default rate; and
	where the calculation cannot be completed because an application for a variation is outstanding, using an interim rate.
62.The system of default rates will allow the CSA to get maintenance flowing quickly where there is no information about the non-resident parent's current earnings. It is intended that these will be set at 15%, 20% or 25% of average non-resident parent’s weekly earnings (currently around £200) according to the number of qualifying children.
63.When the information needed to complete a proper assessment is provided, the default rate will be replaced by a new maintenance calculation. For non-co-operative non-resident parents, maintenance liability for the past will only be recalculated if the full rate is higher than the default maintenance rate. This will both provide an incentive to those non-resident parents to provide information quickly and avoid creating overpayments which have to be recovered from the parent with care.
64.The interim rate will be set at the same level as the normal maintenance calculation pending a decision on the variation application. If a variation is allowed, the interim rate will be replaced, with retrospective effect, by the new rate of maintenance liability resulting from the variation.
65.This section substitutes a new section 12 of the 1991 Act which provides for decisions to set liability at a default or interim rate. The section provides the power to make regulations which will define the way that these decisions are made and subsequently altered.
Part 1: Child Support. Commentary on Sections Schedule 1: Calculation of weekly amount of child support maintenance Section 4: Default and interim maintenance decisions