SolvedCH26880 | Information & Inspection Powers: Penalties: Penalty assessments: When is the penalty payable
From HM Revenue & Customs · Compliance Handbook
The initial, daily, increased daily or tax-related penalty or penalty for inaccurate information or documents charged by an assessment must be paid within 30 days. The 30-day period begins on the date the penalty assessment is issued.
The person may appeal against an assessment of an initial, daily or increased daily penalty or penalty for inaccurate information or documents. If an appeal is made, the penalty must be paid within 30 days beginning on the date the appeal is finally decided or the person withdraws it.
An initial, daily, increased daily or tax-related penalty or penalty for inaccurate information or documents is collected, and collection may be enforced, as if the penalty is income tax charged on an assessment and due and payable. It does not matter which kind of tax position you are checking.