The official documentation to disputing a Tax Credit overpayment is repetitive and not very forthcoming. In an attempt to bring some transparency to disputing your Tax Credit overpayment bills, we have pieced together 7 steps as the suggested route through the process. You can get to these steps, and other important articles, by clicking on the mini-menu bars (like below) on each page.
Although the Dispute process seems long, it's not that you have to do everything at once. Most of it is waiting for one process to finish before another one can start. Remember that we are on your side and don't expect Jo(e) Public to understand a hugely flawed system when those in charge of it do not. So even if your case does not involve massive errors on their part, if you did not understand what was happening to your Award then you have a right to dispute being made responsible for the overpayment.
Please note that there is not actually a very well defined route through this process. Sometimes you may be bounced back and forth, out of order, between the likes of the Adjudicator and your MP. As you will see the whole process is very long and drawn out, but during that time HMRC cannot (read "should not"; but you can get it stopped if they try) recover money, add fees or summons you to court.
We have not yet dealt with anyone who has gone through ALL of the steps and still had to repay. This process has so far taken us over 3 years! We (TCC) hope to have won reform of the system before too long, so one aim should be to string this process out and avoid repayment long enough to get the reform and amnesty in place.
A few tips for you:
There are also Other Organisations that can give you information and guidance about Tax Credit Overpayments, and the Government website 'Directgov' has a page about How to Complain to HMRC.