February

1st - £100 penalty if 2010 Tax Return not yet filed. Additional penalties may apply for further delay. Interest starts to accure on 2009/10 tax not yet paid.
2nd - Quarterly submission date of P46 (Car) for quarter to 5 January
14th - Last date (for practical purposes) to request NIC deferment for 2010/11
28th - Last day to pay any unbalance of 2009/10 tax and Class 4 NICs to avoid an automatic 5% surcharge