Millions of Brits risk a hefty fine if they don't meet a looming national deadline. Many of us don't really have to think about our taxes , and are used to deductions automatically showing on our payslip. It may be slightly frustrating to see your parts of your wage taken away for National Insurance, Tax , and pensions - but at least we don't have to work out the calculations ourselves. However, around 12 million people have to sort their own taxes out, by filling in a Self Assessment form for