GOV.UK
Closing the Examination: Calculating the Overpaid Credits - The Amount
In the majority of examinations the adjustment to the claim will not lead to an in-year recovery of overpaid credits (see CCM8125). For pre-award examinations there will have been no credits paid out before you reached your conclusion. In post-award examinations most potential overpayments will be reviewed following the Section 17 end of year declaration and only the net amount overpaid at the end of the year will be recovered.
The only time you will need to calculate the overpaid credits is where there was never any entitlement to the credits for the period of award or an earlier year is included in your settlement. Where there was no entitlement to the award the overpayment arising as a result of the basic eligibility criteria not being met is recoverable in-year. The guidance at CCM8125 tells you when you can recover an overpayment in year and the examples at CCM8129 show you how the NTC system might recover part of the overpayment. You should follow this guidance to arrive at the amount of overpayment, if any.