CH72260 - Penalties for Failure to Notify: Types of failure to notify: Level of proof
You must clearly establish that there has been a failure and whether the failure was deliberate from the facts.
You must also consider whether the taxpayer has established that there is a reasonable excuse for the failure.
Although we accept that proceedings for certain penalties are criminal for the purpose of Article 6 of the European Convention on Human Rights, see CH300000+, the civil standard of proof continues to apply to such cases. This standard of proof is the balance of probabilities.
This means that if the failure to notify is non-deliberate you must have sufficient evidence to show that the failure occurred and when. If the failure to notify is deliberate you will also need sufficient evidence to show that the failure was, on the balance of probabilities, deliberate. The quality of evidence should be higher for the more serious behaviour.