CH54300 - Assessing Time Limits: Onus of proof and level of proof

Where the assessing time limit depends upon the behaviour that lead to the failure or inaccuracy, see CH53300 and CH53600, you will need to establish why and how the failure or inaccuracy occurred.

You need to establish whether the inaccuracy or failure occurred

  • despite the person taking reasonable care, or
  • because of the person’s careless behaviour. This includes not telling us of
  • an inaccuracy made despite taking reasonable care without unreasonable delay after discovering it, or
  • a failure to notify liability to income tax, capital gains tax or corporation tax without unreasonable delay after any reasonable excuse for the failure had ceased, or
  • because of the person’s deliberate behaviour.

The onus of proof of careless or deliberate behaviour is on HMRC.

Level of proof

The level (or standard) of proof is the balance of probabilities. This means that on the evidence, it is more likely than not that the inaccuracy or the failure to comply with an obligation was made carelessly or deliberately.

Whilst the standard of proof is the same whether the inaccuracy or failure is careless or deliberate, the quality of evidence should be higher for the more serious behaviour.

You will find further guidance on the onus and level of proof in the guidance on penalties for inaccuracies at CH81180 and CH81190, and failure to notify, CH72240 and CH72260.