Tax credits toolkit | CPAG

Tax credits toolkit

16 August 2018

What to do when things go wrong with tax credits

See our factsheet, Tax credits: challenging decisions for more detail on how to identify what decision has been made on your tax credits. If you have been overpaid, the first thing to do is to check whether the decision which created the overpayment is correct. See our factsheet, Tax credit overpayments for more detail on overpayments.


If you think the decision on your entitlement to tax credits is wrong, use form WTC/AP to request a mandatory reconsideration of the decision. This includes where you have been refused tax credits, or your award has been stopped, or you think you were correctly entitled to some or all of the amount that HMRC says has been overpaid,

After the mandatory reconsideration, if you are still unhappy with the outcome, use form SSCS5 to appeal to the First-tier Tribunal.

If you accept that you have been overpaid tax credits but do not think you should have to repay the overpayment, use form TC846 to dispute the overpayment.

If you are a representative acting on behalf of a client use form TC689 to obtain their signed consent.

Follow the links for the online versions, or print off the PDFs at the bottom of this page.


If you disagree with a decision on your claim, or you think that HMRC has acted unreasonably or unlawfully, caselaw may help. Sign up to our monthly e-bulletin for summaries of relevant decisions by the Upper Tribunal which are binding on First-tier Tribunals and HMRC decision makers.

See 'Tax credits caselaw by subject' for cases collected under relevant subject headings, including 'undisclosed partners', 'main responsibility test' and 'backdating'.

See 'Tax credits caselaw list' for a list of all decisions with a summary and link to full decision.


HMRC has extensive staff guidance available online. Useful sections include:


If you have a complaint, it is best to put this in writing - see HMRC factsheet C/FS for information. It may help to involve your MP.

If you have exhausted HMRC's complaints procedure, you can take the matter to the Adjudicator's Office. The Adjudicator can recommend compensation, or that overpayments are written off. The annual report 2014 said that HMRC must take into account the claimant's circumstances and ability to comply, and be mindful of the effect of its actions on vulnerable claimants. See our factsheet, Tax credits and complaints for more information.