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Universal Credit (UC) is gradually replacing tax credits, and some other social security benefits. Universal credit is now available across the UK and HMRC state that it is no longer possible for anyone to make a brand-new claim for tax credits. The only exception is for certain people who are granted refugee status. Instead, people are expected to claim UC or pension credit depending on their circumstances.  Currently, existing tax credit claimants can continue to renew their tax credits and/or add extra elements to their claim. See our existing tax credit claimants page for more information. Our understanding is that the majority of existing tax credit claimants will move to either universal credit or pension credit by the end of the 2024/25 tax year. You can find out more about this in our universal credit section. 

Updated on 6 April 2024

Tax credits complaints

Sometimes the only way to sort out any problems with a tax credits claim is to make a formal complaint. We explain how to complain to HMRC and the different complaint stages.

Various folders in a pile, the top folder reads 'COMPLAINTS' on the spine.
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You may want to complain if, for example, the advice you have had from HMRC staff has been poor or misleading, mistakes have been made, there have been long delays, or you are just not happy with the service you have received.

A lot of tax credits complaints are about having to pay back an overpayment. There are other ways to challenge a decision about an overpayment, such as by appealing or disputing.

HMRC’s code of conduct

The HMRC Charter sets out the standards of behaviour and values you should expect from HMRC staff. You can see the Charter in full on GOV.UK. This might be a useful starting point when writing a complaint letter, especially if it can be shown that HMRC have not met their promised standards.

Complaint stages

Making a complaint is a formal process and has a number of stages.

Informal complaint

You can ask to speak to a team leader or manager to start with; this can sometimes resolve the situation. If this does not resolve your problem then you will need to start the complaints process by sending HMRC a Tier 1 complaint (first review).

Formal complaint (first tier complaint)

A formal letter of complaint should be sent to the Complaints manager at HMRC, tax credits. You should write ‘complaint’ at the top of the letter and make sure you keep a copy of your letter. This is your tier 1 complaint (it might be referred to as a 'first review').

Although it is best to put your complaint in writing, you can phone HMRC’s tax credits helpline instead. If you do this, make sure you say you are making a formal complaint. You should also make a note of the date, time and details of your phone call in case you need to refer to it again.

You can also make a complaint to HMRC online via GOV.UK. Again, you should keep a copy of your complaint and make a note of the date and time that you send it.

Your complaint will be given to a caseworker to investigate. You should be given the name and contact details of your caseworker. They should also make attempts to keep in touch with you until your complaint is resolved or it moves on to the next stage.

Formal complaint (second tier complaint)

If you are unhappy with the response from the caseworker, you can make a tier 2 complaint by asking for a senior officer to review your complaint. Again, it is best to ask for this in writing so that you have a record, but it can be done by phone or online.

This is the second tier of the formal complaints process. The response you get at this stage is the end of HMRC’s internal complaints procedures.

Complain to the Adjudicator’s Office (third tier complaint)

If you are unhappy with HMRC’s final response, you can make a tier 3 complaint by asking the Adjudicator’s Office to investigate your complaint.

You must contact the Adjudicator’s Office within six months of HMRC’s final response.

To make a complaint to the Adjudicator’s Office you should write to them including:

  • details of your complaint and your reasons for complaining
  • a copy of the final decision letter from HMRC (Tier 2 response).

You can contact the Adjudicator’s office using the online form on their website or you can write to the Adjudicator at:

The Adjudicator's Office, PO Box 11222, Nottingham, NG2 9AD

The telephone number is 0300 057 1111 and there is more information on the Adjudicator’s Office website.

Parliamentary Ombudsman

In most cases, you can only make a complaint to the Parliamentary Ombudsman once you have had a response about your complaint from the Adjudicator’s Office.

You cannot go directly to them yourself; you must ask your MP to make the complaint on your behalf. There are rules about the timescales relating to the Ombudsman which say that the complaint must be made to the MP not later than 12 months from the day on which the person complaining first had notice of the matters alleged in the complaint, but the Ombudsman may still look into the complaint made outside that period if they consider that there are special circumstances which make it proper to do so.

You can download a form from the Parliamentary Ombudsman website that may be used to send complaints to your MP.

Dealing with your complaint

Any of the following outcomes could apply as a result of a complaint:

  • an explanation from HMRC
  • an apology from HMRC
  • an explanation of what went wrong
  • mistakes corrected (and any money due paid)
  • payment of costs (for example, postage, phone calls, travel expenses)
  • a payment for anxiety and distress that came about as a result of HMRC errors or delays – these usually range from £25 to £500
  • HMRC saying you do not have to pay back an overpayment.

It is a good idea to say in your complaint letter what solution you ideally would like, although there is no guarantee HMRC will follow this.

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