In Hans Solvkjaer v HMRC [2020] TC07933, the First Tier Tribunal (FTT) dismissed the taxpayer’s application for permission to make a late penalty appeal: there was no compelling evidence to justify one.

A Late appeal is allowed under s.49 TMA 1970 where either: 

The FTT dismissed the application to make a late appeal, finding that:

Useful guides on this topic 

Appeals: Late
When can you make a late tax appeal? What conditions must be met? 

Appeals: Grounds for Appeal Toolkit
What grounds are there to appeal a tax penalty? How can you word a tax appeal? Can you appeal HMRC errors? What is a reasonable excuse?

How to appeal a tax penalty
What are the steps in making an appeal? What should your appeal cover? What does recent case law say on this topic?

External link 

Hans Solvkjaer v HMRC [2020] TC07933