By Charlotte Beugge

Taxpayers beware: the 31 January deadline for remitting your 2010-11 tax return and paying the tax you owe for that year is just three weeks away.

According to Unbiased.co.uk's TaxAction report, last year taxpayers were fined £368 million for late returns, incorrectly filled in forms and surcharges for late payment of tax from previous years. Of this, £116 million were for late returns.

If you don't get your return in by 31 January, then you are automatically fined £100. A further £236 million was levied in charges for miscalculation on tax forms and £16 million in surcharges for late payment of tax from previous years.

If you still haven't filed your tax return three months after the 31 January deadline then the penalty is £10 for each day up to a maximum of £900 - plus the £100 penalty. If by 29 July the form has still not been returned, then there is another penalty of £300 or 5% of the tax due, whichever is the higher.

Karen Barrett, chief executive of unbiased.co.uk says: "The rules of self-assessment forms remain unforgiving for taxpayers who return their forms incorrectly or who fail to meet the deadline. The monetary penalties are hefty and in most cases additional surcharges are often imposed."

Anyone now still to file their return will have to do so online, as the deadline for paper returns expired on 31 October. And although the final deadline for returns is 31 January, if you wanted HM Revenue & Customs to collect any tax you owe through your code you had to get your return in by 30 December 30.