Thanks.

I have calculated that you should have paid tax in 2011/12 of £1,179.40. Check your 2011/12 P60 to see how much tax was deducted.

For 2010/11, you should have paid tax of £965.60 so you are underpaid by £145.60 based on the figures you gave me.

For 2009/10, you should have paid no tax if you had no income other than state pension and jobseeker's allowance. You will need to call the tax office and ask them how they arrive at their figures as they appear to be saying that you earned £3,541 in one month. They do make many mistakes.

If you look at the tax calculation for each year, you will probably see that the underpayment for 2009/10 of £411.40 has been carried over to the 2010/11 calculation and added to the £145.60 underpayment I have calculated to give a total of £557.00 which is close to the figure of £556.80 you mentioned in initial question. So, at worst, you owe £556.80, not £968.20 (£411.40 + £556.80).

When you call the tax office, ask them to review your 2012/13 tax code and to make sure it includes the correct amount of state pension as a deduction from your personal allowance of £8,105.

Let me know if you have any further queries.