CH401292 | Charging penalties: introduction: offshore matters: requirement to correct: failure to correct penalty
From HM Revenue & Customs · Compliance Handbook
If a customer fails to correct their position by 30 September 2018 (or the extended deadline mentioned at CH123200) they are liable to a failure to correct penalty (FTC).
The standard FTC Penalty is 200% of the tax liability that should have been corrected.
The penalty can be reduced if a disclosure is made and you should determine:
the quality of disclosure (see CH401293 disclosure page), and
whether it was a voluntary or non-voluntary disclosure.
The penalty cannot be reduced to an amount lower than 100% of the tax liability or 150% if the disclosure is non-voluntary, unless there are special circumstance see CH123350
In addition to the standard FTC penalty of 200% the person may also be liable to an additional:
Reasonable excuse
We will not charge a failure to correct penalty where HMRC are satisfied that there is a reasonable excuse for the failure see CH123300