Readers' forum: Penalty shoot-out

My client is thinking of selling his business and has been reviewing old accounts and tax returns. He has realised that four years ago he missed the sale of a buy-to-let property from his tax return (he has a large portfolio of these properties and sells several each year). This was not deliberate but it is difficult to say that it wasn’t careless. I have advised him to make a full disclosure.

He has asked me about penalties when he makes the disclosure. I am certain that the disclosure will be comprehensive and that he will pay the tax due and co-operate fully with HMRC to conclude matters. However I am aware of the HMRC compliance checks factsheets that sets some changes to the way penalty charges are calculated (tinyurl.com/y8dp55u5).

Do I say that given that the inaccuracy is being corrected within a couple of months of...