We had a case recently where the award of tax credit was made, paid, then revised. Although there was still an award for the year, no further payments would be made, as the claimant has already been paid full entitlement for the year, and there is an overpayment.
The answer I received for dealing with this is ‘if the award is nil, then there is nothing to take into account from the Monday following the date of the last instalment. Although tax credit is an annual award the assessment of HB/CTB is based on the weekly income received at the time of the assessment. The overpayment of TC will be adjusted in some way over the next year, so the overpaid amount is ignored’.
Hope this helps in part of your query!
Fiona.