How to complain about HMRC and escalate to the Adjudicator

If you are unhappy with how HMRC has handled your tax credits, Child Benefit or Guardian's Allowance claim, the route runs in a fixed order: write to the person dealing with your case, ask for the complaint to be passed to an HMRC customer service adviser, and only then ask the Adjudicator to look into the matter¹. HMRC operates a tiered complaints system, and complaints go through two tiers of service before they can leave the department².

The Adjudicator's Office is the third stage, and it covers both HMRC and the Valuation Office Agency³. You must contact it within six months of HMRC's final response⁴. Beyond that sits the Parliamentary and Health Service Ombudsman, which you reach through your MP, and which you must approach within one year of becoming aware of the matter⁵.

The same shape applies to statutory pay. Where an employer refuses to pay Statutory Sick Pay, or will not give the form explaining why, the route is a complaint to HMRC, and the deadline is six months from the date the SSP should have started⁶.

Complain to HMRC first: start with the person handling your case

There is no way round the first stage. The Adjudicator's Office only becomes available once HMRC has given its final response, so a complaint has to go into HMRC and come back out again before anything else can happen⁴. For Tax Credit, Child Benefit or Guardian's Allowance claims the sequence is specific: write to the person dealing with your case, then ask for the complaint to be passed to an HMRC customer service adviser, then ask the Adjudicator to look into the matter¹.

Put the complaint in writing and keep a copy. That is the pattern independent advisers recommend for complaints generally: complain in writing to the organisation, keep a copy, and send a copy to the right regulator or ombudsman if it is not resolved⁸. The same discipline applies here, because the Adjudicator will want to see what you sent HMRC and what came back.

Where the disagreement is about a decision rather than about service, HMRC offers three ways to try to resolve the case: an internal review, an alternative dispute resolution, or a First Tier Tax Tribunal⁸. Those are the routes for challenging the decision itself, and they are separate from the complaints route described here. If your complaint is about a payment plan HMRC has refused, you cannot formally appeal the decision, but you can make a complaint and ask for the case to be reviewed, and then ask for it to go to the Adjudicator's Office⁹.

One thing worth knowing before the complaint escalates: HMRC does not need a court order to take bailiff action against you, and can apply to court for a warrant to break in¹⁰. A complaint does not pause enforcement by itself, so it is worth dealing with the underlying debt at the same time. Free, impartial help is available from TaxAid and from the debt advice charities.

When HMRC reviews its own decision: the second tier

The second tier is HMRC looking at its own handling of the case again, through a customer service adviser rather than the person who dealt with it first¹. This is the stage where a complaint is most often resolved, and it is also the stage that produces the "final response" the Adjudicator needs to see.

For decisions rather than service failures, the parallel process is a mandatory reconsideration. On Child Benefit, for example, you can ask HMRC to look at the decision again, which is called a mandatory reconsideration, and then appeal to an independent tribunal¹¹. Tax credits overpayments work in a similar way: if you do not agree that you have been overpaid, or that the amount is correct, you may be able to appeal¹². HMRC expects a dispute about an overpayment to be started within three months of the decision, whether that is the notification of the overpayment, the outcome of the mandatory reconsideration or the appeal decision¹².

If you are an appointee finalising someone else's tax credits, check that the information in the person's Annual Review letter is correct, and contact HMRC before the deadline in their letter if it is not¹³. Tax credits have ended, so most live disputes now concern overpayments being recovered rather than new awards¹³.

Escalating to the Adjudicator's Office within six months

The Adjudicator's Office is the third tier, and it is the point at which someone outside HMRC looks at how the department behaved. You must contact the office within six months of HMRC's final response⁴. That deadline is the one that catches people out, because it runs from HMRC's letter, not from when you get round to reading it.

The Adjudicator covers HMRC and the Valuation Office Agency³. It does not cover the tax tribunal system, and it does not replace an appeal. If your underlying dispute is about how much tax is owed, the tribunal is the route; the Adjudicator is about the service you received while that dispute was handled.

Deadlines elsewhere in the tax system vary, which is why the six-month figure matters. A dispute about a tax credits overpayment is expected within three months of the decision¹². A Self Assessment return that HMRC has not withdrawn still has to be filed by the due date, even with no income to report, and penalties for failing to file on time still apply¹⁴. A Simple Assessment letter gives you 60 days from the date of the letter to let HMRC know if anything does not look right¹⁵.

What to send the Adjudicator

The Adjudicator is deciding whether HMRC handled your case properly, so the evidence is about the handling, not just the outcome. Send the complaint you made to HMRC, HMRC's final response, and a short account of what you think went wrong and what you want to happen.

Keep the file complete. Independent advisers recommend keeping a copy of every complaint you send and copying in the right regulator or ombudsman where a complaint is not resolved⁸. The same principle applies to the Adjudicator: a clear chronology with dates, letters and reference numbers does more work than a long argument.

If the complaint involves a scam or a suspicious contact, the reporting route is separate. Forward suspicious emails claiming to be from HMRC to phishing@hmrc.gov.uk and texts to 60599¹⁶. HMRC may send you a text message if you request a Self Assessment tax refund, to say that your refund is being processed and when you can expect to get it, so a text is not automatically a scam¹⁷.

Beyond the Adjudicator: the Parliamentary Ombudsman

The final stage is the Parliamentary and Health Service Ombudsman. After going through all the earlier steps, you can ask your Member of Parliament to refer your case to the Ombudsman¹⁰. You begin a complaint by completing the online form and sending it to your MP, and you need to do this within one year of becoming aware of the matter⁵.

That one-year limit is longer than the Adjudicator's six months, but it runs from a different starting point, so the two do not line up neatly. The practical sequence is: HMRC first, then HMRC's review, then the Adjudicator within six months of the final response, then the Ombudsman via your MP within a year of becoming aware¹.

The same MP referral route applies to some court-related complaints. If you have followed the court's complaints procedure in full and are unhappy with the response, you can ask your MP to refer your complaint to the Parliamentary and Health Service Ombudsman¹⁸.

For complaints about Council Tax banding rather than HMRC, the route is different again. Take your complaint further to the Valuation Tribunal if you are unhappy with the response, and then to the ombudsman services¹⁹. Ask the Valuation Office if you want to know whether changes to your property will affect your Council Tax band¹⁹.

Complaints about Statutory Sick Pay and your employer

Statutory pay complaints follow the same first step but with a different department inside HMRC. If you disagree with a Statutory Sick Pay decision made by your employer, you can contact HMRC's Statutory Payments Disputes Team²⁰. If your employer will not give you an SSP1 form, or you do not agree with their reasons, you can complain to HMRC⁶.

The form matters. Where there is no agreement about SSP, the employer can be asked to give their reasons for not paying it in writing, which they should do on a form called SSP1, and the SSP1 form is needed before calling HMRC⁶. The complaint has to be made within six months of the date SSP should have started⁶.

The same team handles maternity and paternity disputes. Where an employer's decision on Statutory Paternity Pay is thought to be wrong, the HMRC employees enquiry line is the contact²¹. HMRC can also be asked to pay Statutory Maternity Pay where the employer has refused to pay, has dismissed the employee to avoid paying SMP, or has gone into liquidation²². The contact with HMRC is within six months, but HMRC has discretion to accept a later claim where there are good reasons for being late²³.

If you are not happy with HMRC's decision on your employer's behalf, call HMRC, and if they think you are right they will challenge your employer⁶. That is a different mechanism from a complaint about HMRC's own service, and it is the one that gets the money paid.