ESC A19 is an extra statutory concession that lets HMRC give up arrears of Income Tax, Capital Gains Tax and Class 4 National Insurance when the arrears arose because HMRC failed to make proper and timely use of information it was given by you, your employer or pension payer, or the Department for Work and Pensions. You must also have reasonably believed your tax affairs were in order, and normally HMRC must have told you about the arrears more than 12 months after the end of the tax year in which it received the information. You ask by phone or letter, ideally before paying anything.

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What does ESC A19 actually cover?

The concession is a statement of HMRC policy rather than law. Its text, reproduced at PAYE95005 in HMRC’s PAYE Manual, says arrears may be given up if they result from HMRC’s failure to make proper and timely use of information supplied by:

  • the taxpayer, about their own income, gains or personal circumstances (information sent by an agent counts as coming from the taxpayer);
  • an employer, where the information affects the taxpayer’s tax code (a pension payer is treated as an employer for this purpose);
  • the Department for Work and Pensions, about State Pension, disability benefits, Employment and Support Allowance or a widow’s pension.

Only personal Income Tax, Capital Gains Tax and Class 4 National Insurance are within scope (PAYE95010). VAT, Corporation Tax and other taxes are not. HMRC also expects the arrears to be genuinely HMRC’s fault. If the underpayment came from an employer using the wrong code or failing to follow the P45 and P46 procedure, HMRC pursues the employer instead (PAYE95011).

The concession also covers an over repayment that HMRC tells you about more than 12 months after the end of the tax year in which the repayment was made, provided the delay came from HMRC’s failure to use information and the reasonable belief test is met. A repayment sent to the wrong person, or one that exceeded the tax actually paid, is not arrears and cannot be given up (PAYE95040).

Self Assessment cases are treated differently. Because of the statutory filing deadlines and the greater responsibility placed on the taxpayer, HMRC says ESC A19 does not normally apply to them (PAYE95001). Most successful claims involve PAYE tax codes and the P800 calculations that follow them.

What counts as HMRC failing to act on information?

HMRC’s guidance at PAYE95045 links “proper and timely use” to its expected business process. The information must be the kind that should have prompted a review, typically a change to your PAYE tax code. Common examples are a second job or pension, a new company car or medical benefit, or the start of State Pension.

Two points in the guidance often decide a claim:

  • Timely use is measured from the year the arrears relate to. HMRC treats itself as having acted in time if it notifies the arrears within 12 months after the end of the relevant tax year, even if it ignored the information for longer than that.
  • Information must reach the right place in a usable form. If you say you told an unconnected part of HMRC, or gave the information in a way HMRC could not reasonably act on, the claim should be refused. Where there is no trace of your contact, HMRC is told to give the benefit of the doubt if it is likely the information was received.

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How does the 12 month rule work?

For each underpaid year HMRC works out a cut off date: 12 months after the end of the tax year in which it received the information (PAYE95050). If you were told about the arrears after that date, the normal limb of the concession can apply. HMRC’s public guidance says tax owed from the last tax year is unlikely to be written off, whenever HMRC received the information.

Arrears for the last tax year can be given up only in exceptional circumstances. All of these must apply:

  • HMRC failed more than once to make proper use of information about the same source of income;
  • it is the first time HMRC has told you that you owe tax for an earlier year, and the reason for that earlier debt and the last year’s debt is the same;
  • the arrears have built up over two whole tax years or more;
  • you reasonably believed your affairs were in order.

HMRC reads “one source of income” as one aspect of your tax affairs (PAYE95070). Repeated failures include ignoring the same information at the annual coding review. A taxpayer who receives a P800 underpayment notice every year is unlikely to qualify, because HMRC has acted “in time” each year even if it never fixed the code. Example 5 at PAYE95075 shows a widow in exactly that position being refused.

What does “reasonable belief” mean?

HMRC says the question is not whether you believed your affairs were in order, but whether it was reasonable to hold that belief (PAYE95080). The factors at PAYE95081 include:

  • Size of the arrears. The larger they are compared with your total tax, the harder it is to argue you noticed nothing. A higher rate taxpayer whose net pay rises sharply after a job change is HMRC’s own example of someone who should have questioned it.
  • What HMRC sent you. Coding notices and letters are expected to be read. Saying you did not understand them is not enough on its own.
  • Misleading reassurance. One piece of wrong advice, such as confirmation that your code was correct, can be enough to satisfy the test.
  • Muddled records. Numerous or incorrect codes issued by HMRC count in your favour.
  • Professional representation. If an agent acted during the build up, HMRC expects the agent to have spotted the problem.
  • Your understanding of tax, including age, background and health. Being too busy is expressly ignored.

Reasonable belief can change over time, so HMRC may give up some years and collect others. If the decision is finely balanced, the guidance says the taxpayer should get the benefit of the doubt.

How do you ask HMRC to apply the concession?

GOV.UK says you can apply by calling or writing to HMRC, and you should do so before paying any of the tax. Tell HMRC:

  1. which arrears you dispute, including the tax years;
  2. what information HMRC should have acted on, who supplied it and when;
  3. why you thought your tax was up to date.

Copies of letters, call dates and coding notices make the claim far stronger. If you have already paid, a refund is still possible in limited cases: where you made a payment on account when you complained, where an earlier refusal is overturned, or where HMRC accepts you felt coerced or misled into paying before your request was reviewed (PAYE95010). HMRC considers only the net underpayment for a year, so any extra relief it finds is netted off first, and an overpayment for another year is set against arrears that are not given up (PAYE95035). Arrears that are not written off can usually be collected through your tax code; see coding out underpaid tax.

HMRC confirms the outcome in writing, with letter OCA60 for acceptance or OCA61 for refusal.

What if HMRC refuses?

There is no statutory right of appeal against a refusal to apply ESC A19 (PAYE95090). You can ask HMRC to review the decision, explaining why you disagree and adding any new information. If that fails, a further objection is treated as a complaint about HMRC’s handling. After the internal complaints process you can go to the Adjudicator, or through your MP to the Parliamentary Ombudsman, who will check that HMRC applied its guidance fairly and consistently. Our page on escalating issues with HMRC covers that route.

A worked example

Illustration only. Priya started drawing a small occupational pension in June 2022 alongside her salary and phoned HMRC that month to report it. HMRC did not amend either tax code, so both sources received a full Personal Allowance. Her codes stayed unchanged at each annual review. In August 2026 HMRC reviewed her record and sent calculations for 2022 to 2023, 2023 to 2024, 2024 to 2025 and 2025 to 2026 at the same time.

The first three years were notified more than 12 months after the end of the year in which HMRC received her call, so the normal limb can apply. The 2025 to 2026 arrears were notified in time, but HMRC failed more than once on the same source, this is the first notice of earlier arrears for the same reason, and the arrears built up over more than two whole tax years. The exceptional limb can therefore apply too, provided HMRC accepts Priya reasonably believed her tax was right. This mirrors Example 1 at PAYE95075.

What mistakes do people make?

  • Paying the bill first and then asking, which makes a refund harder to obtain.
  • Claiming for a year where HMRC sent a P800 within 12 months of the year end. That is treated as timely, however long the code stayed wrong.
  • Relying on a vague memory of a call. Dates, names and copies of letters carry far more weight.
  • Asking for the concession on employer mistakes, Self Assessment errors or taxes outside its scope.
  • Ignoring changes in pay that should have raised questions, which undermines reasonable belief.
  • Treating a refusal as final. A review and then the complaints route remain open. For the wider history of concessions, see extra statutory concessions.

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Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 19 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.