HMR&C have decided that the £100 penalty for late payment was not working,they will now fine you even if you do not owe any tax,and if you have filled in the form to send back.For later payments,they view it that you are borrowing their money,and add 10% interest to borrow it,plus add on late penalties as time goes by.No many organasations go that high in interest rates,the final option is they close the firm down.
Lets face it the are quite right in their thinking, if you owe them money and aint paid it then your borrowing their money simples 
There’s not really any excuse for HMRC to wait for tax returns, they are sent out early enough and you have a month after the finish of the tax period to return them.
There should be no excuse for filing a late Return. If filing online, you have until 31st January following the end of the tax year, almost 10 months to get the Return in, or if you still prefer to do it on paper, until 31st October following.
That should be plenty of time. After all, most peoples Tax Returns can be completed in a very short time. (My year end accounts and Tax Return take about 2 hours to complete!)
Anybody who gets a penalty these days must be just plain lazy!