Taxpayer successfully argues against “deliberate behaviour” penalty
When it comes to tax penalties, there is a behaviour-based scale that means you pay more for knowingly understating your tax bill than if you make a simple mistake. Unfortunately, HMRC is often over-zealous to apply a “deliberate” tag. Why is this a problem and how did one taxpayer successfully argue against it?
There's a largely harmonised penalty regime for inaccuracies across different taxes, including income tax. Broadly:
- a penalty arises because of a lack of reasonable care, the penalty will be between 0% and 30% of the extra tax due
- the error is deliberate, the penalty will be between 20% and 70% of the extra tax due
- the error is deliberate and concealed, the penalty will be between 30% and 100% of the extra tax due.
However, this isn’t the end of the matter - the behaviour also determines how far back HMRC can issue an assessment for. The ordinary time limit is four years, but if the behaviour is careless this increases to six years. If the inaccuracy arises due to deliberate behaviour (which can include negligence), the time limit is 20 years. HMRC seems to argue that most errors are at least careless, but in some cases it tries to go one step further, as Mr Collier (C) found out.
C had genuine conditions that affected his ability to read, and so he relied heavily on an accountant to submit his personal and partnership returns. There were some omissions following the accountant suffering a family tragedy, which HMRC picked up after a long investigation, and raised assessments and penalties on the basis of “deliberate” behaviour. C didn’t dispute the assessments for the tax, but argued that the behaviour was careless, not deliberate so the assessments (which were issued more than six years after the end of the relevant year) were out of time. The Tribunal’s view was that C had not acted in a reckless way, and there were genuine reasons for the omissions. HMRC had not met the burden of proof required, and C’s appeal was allowed.
Related Topics
-
HMRC updates advisory fuel rates from 1 March 2026
HMRC has published the latest advisory fuel and electric rates (AFRs) for company cars, effective from 1 March 2026. Several rates have changed since the previous quarter. What should employers be aware of?
-
5 April deadline approaching for key tax relief claims
With the end of the 2025/26 tax year now less than seven weeks away, business owners and company directors should remember that several valuable reliefs and elections must be made before 5 April. Which opportunities are about to close?
-
HMRC reminds employers about payrolling benefits deadlines
HMRC is reminding employers of key dates and preparations ahead of the transition to real-time payrolling of benefits in kind (BiKs). With an important voluntary registration deadline approaching, what do payroll teams need to know?

This website uses both its own and third-party cookies to analyze our services and navigation on our website in order to improve its contents (analytical purposes: measure visits and sources of web traffic). The legal basis is the consent of the user, except in the case of basic cookies, which are essential to navigate this website.