CH414300 | Charging penalties: appeals: inhibiting debt management action
From HM Revenue & Customs · Compliance Handbook
We do not require payment of disputed penalties in any regime until the dispute is resolved.
If you receive an appeal against a penalty (direct tax) or a request for a review (direct or indirect tax) you must make arrangements to inhibit debt management action.
If, after the dispute is resolved following agreement with the person, review or tribunal decision, a penalty is still payable, you may need to amend the penalty assessment and/or remove the inhibit on debt management action.