Have you remembered that if you missed the 31 October filing date for your 2010/11 paper tax return, then you must file online by 31 January 2012?
The penalties for late filing are now much higher than they used to be – the starting point is £100, even if you owe no tax. 31 January is also the date for paying any outstanding tax due for 2010/11 and the first payment on account for 2011/12. If you expect to pay less income tax for 2011/12 than 2010/11, you can make a claim to reduce your payments on account using HMRC form SA303. The FSA does not regulate tax advice.