I have just taken two new clients and I have had to sort out appeals on both. First one was for a penalty for late filing of Ct600 The company was and is still dormant but the previous accountant filed a CT41g but instead of using the "Dormant Co" one filed the active one. Next Partnership penalties for late filing of return on a "new partnership" Old partnership had not ceased but form SA400 filed instead of SA401.
HMR%C are sympathetic and are granting the appeals but have had to forward a SA370 as it will need management approval So please check the forms you are submitting as HMRC may not always be so helpful