What is the difference between careless and deliberate behaviour?

HMRC sorts every inaccuracy into one of several behaviour categories: reasonable care, careless, deliberate, or deliberate and concealed. Each carries its own penalty range, and the categories are not interchangeable labels.

Careless behaviour means you didn't take the care a prudent, reasonable person would take with their tax affairs, even though you weren't trying to underpay. Deliberate means you knew the figure was wrong and submitted it anyway. Concealed goes further still, adding steps taken to hide the inaccuracy, such as false invoices.

The distinction matters enormously because the statutory percentage ranges rise sharply from one category to the next, and deliberate behaviour also extends how far back HMRC can assess you.

Schedule 24 Finance Act 2007 defines these categories for inaccuracy penalties, and the same distinctions carry through to failure-to-notify penalties under Schedule 41 Finance Act 2008.

Reasonable care is judged against what a person in your position, with your knowledge and resources, ought to have done. A sole trader without an accountant is judged differently to a company with in-house finance staff.

Crucially, HMRC carries the burden of establishing deliberate behaviour. It isn't enough for a caseworker to suspect intent; there needs to be evidence, such as inconsistent records or admissions, before the higher category applies.

As director, decisions you made about how income and expenses were recorded are central to this assessment. If your bookkeeper made an isolated coding error, that typically sits at careless, or even reasonable care, not deliberate.

Problems arise when directors knowingly under-record sales or overstate expenses to reduce Corporation Tax. That pattern, repeated across periods, is exactly what HMRC looks for when arguing deliberate behaviour.

If HMRC suggests your case is deliberate and you disagree, push back early and in writing. Accepting the label without challenge locks you into the higher penalty band and the longer assessment window.

Moving from careless to deliberate can multiply the penalty percentage several times over, and moving to deliberate and concealed multiplies it again. The same underlying tax bill produces a very different final cost depending on which category sticks.

Beyond the penalty itself, a deliberate finding opens up an extra decade or more of assessable years, so the total tax at stake can grow substantially, not just the penalty rate.

Growth plan clients have free tax investigation insurance included, which helps cover the professional costs of contesting a behaviour finding — see /fees for what's covered.

Don't agree to a deliberate finding just to move the enquiry along faster. It has lasting consequences for penalties, time limits and, in the most serious cases, potential publication.

Don't assume that a large error automatically means deliberate behaviour. Size alone isn't evidence of intent; HMRC still needs to show you knew.

Don't ignore requests to explain how an error happened. Silence is often read against you when HMRC is deciding which category to apply.