Client, single mother, 2 children, started work 4/03 at £10000 pa, claimed WTC & CTC, got award. 4/04 pay increased to £15000 pa. Client rang TCO to inform them, got award wrongly showing pay as £1500 pa, did not notice this, WTC went up. 4/05 renewal done and large overpayment notified. Despite TCO's elementary error in keying the wrong salary, I don't see any hope of this passing their "reasonableness" test. However, I thought I'd ask if anyone happens (a forlorn hope!) to have succeeded in getting an overpayment written off in any similar circumstances.

I advised on a colleagues ex partner's overpayment of tax credits when I noticed that the assessment included child care costs of £1600 per wk when this was her yearly costs. She advised them of error and in due course was advised of a huge overpayment. They commenced recovery from revised entitlement, but I continued to put forward that it was an official error and the lack of clarity in the award notice as the reason it was not identified. After several months - success, all tax credit reinstated. But no letter advising they had accepted official error. Think that my case mirrors yours very well, so good luck!