31st January
31st January 2012 is the final deadline for submitting your Tax Return for the Tax Year 10-11 if you do it 'Online', HM Customs & Revenue's 'Online calculator' can also work out the amount of tax due for the year.
In order to use this service you must be a registered user of 'Online Services' or alternatively you can authorize an agent to file online for you.
You must also pay the balance of any tax not already paid 'on account' for the Tax year 10-11.
You will also have to pay your first 'Payment on Account' for Tax Year 11-12 by this deadline.
Automatic penalties are charged for late submission of Tax Returns, currently £100 per return, if a partnership return is submitted late, each partner will be charged an automatic £100 penalty.
There are variable penalties for incorrect Tax Returns and interest is charged on tax paid late.