If you are a director of a limited company you need to be submitting your year end accounts to Companies House by 9 months after your year end.
I believe that accounts should be completed within 3 months of the year end so that you know your tax bill and understand your numbers but if you are anywhere near the 9 month mark you need to be aware of the potential fines for submitting late.
It used to be £100 fine but in the 2006 Companies Act, the fines got boosted to:
£150 if you are late
£375 if you are late by more than 1 month
£750 if you are late by more than 3 months
£1,500 if you are late by more than 6 months.
So you can see, it is very expensive not to get the accounts in on time.
It gets worse though. If you are late for a second successive year, the fines are DOUBLED.
Make sure you know when your accounts are going to be completed.