This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Inheritance Tax Manual

Procedures for taking penalties on late accounts: settling the penalty enquiry

Where the taxpayer has provided a reasonable excuse, you need to record the fact that although a penalty was due, it was not taken. This should be done in accordance with IHTM36371 Similarly, when a late account penalty is paid you should record the details on the penalty database.