Charging penalties: calculating penalties: reductions for disclosure: unprompted or prompted
A disclosure is unprompted if it is made at a time when the person making it has no reason to believe that HMRC have discovered or are about to discover the inaccuracy, under-assessment, failure to notify, deliberate withholding of information or wrongdoing. Otherwise it is prompted.
Disclosures made during a compliance check will usually, but not always, be prompted. A disclosure could be considered unprompted if the inaccuracy, under-assessment, failure or wrongdoing disclosed was outside the scope of the compliance check and would not have been found in the normal course of the check.
A disclosure made at the start of a compliance check by a customer because they think that HMRC will discover it later, cannot be unprompted. Such early and complete disclosure is to be encouraged but any credit due must be given by an improved reduction for the quality of the disclosure (telling, helping, and giving access), see CH403203, and not treating it as unprompted.
You should avoid pre-judging whether a disclosure is unprompted or prompted. Judgement should be left until the end of the compliance check, even if you are pressed to do so by the customer or their agent. Further investigation may reveal that what initially appeared to be an unprompted disclosure was in fact prompted.
If the customer claims their disclosure was unprompted because they made earlier contact with HMRC about it you will need to ask them for evidence of this contact. Checking their evidence may mean asking for a Contact Centre recording of a telephone call, so you should obtain accurate information about the date, destination and time of call.
For guidance and examples of how to determine whether a disclosure was unprompted or prompted see