Single parent claims WTC & CTC from April 2003 to the start Nov 2003 when she stops working, notifies IR. All well so far.
Clients partner moves in end Nov 2003, he works so claim for new claim for WTC submitted. IR use partners income from start of 2003, i.e. includes period he did not live with claiment or receive WTC himself, and IR then decide client has received £3000 too much WTC since April 2003!

This seems clearly to be wrong, however this is WTC so I would not be surprised at anything. Anyone else come accross this or can point me in the direction of the legislation that clarifies this scenario?

New benefit, administered by the IR..... we should have seen this coming!

s3(4) of TC Act gives entitlement in relation to couples or single claimants and defines when one claim ends and another commences with a new partner moving in.

The Tax Credit (Income Thresholds and Determination of Rates) Regs 2002 SI 2008 set out the calculation with reference to 'relevant periods' see reg 7 for example. A relevant period is one throughout which the elements in the maximum TC calculation remain the same. Obviously the addition of a second adult element would then trigger a new relevant period so a new calc should be done for that portion of the tax year remaining. Reg 7 also stipulates that the income has to be viewed as the income for that relevant period.

The combination of these two is that the period of award for TC ends when a single person becomes one of a couple and a new calc should be done for the new relevant period.

Just as a last thought try telling the IR that the claimant had a baby part way through the year but wants them to apply the higher baby addition in the family element back to April 2003. When they say they can't, you can say "exactly"!