Q. In July 2011 I sold a property which had been used for my business. I planned to reinvest the proceeds in another property, but that acquisition never happened. I know I should now pay Capital Gains Tax on the gain made in July 2011. How do I go about doing that?

A. The period in which you should have reinvested the proceeds ran out in July 2014, so you do need to pay the CGT due for 2011/12 unless you get the tax inspector to agree to extend the period for reinvestment. He will only agree to an extension if you were prevented from reinvesting by circumstances beyond your control.

The disposal made in July 2011 should have been reported on your 2011/12 tax return as part of your provisional claim for roll-over relief. You should now write to the tax office to withdraw that provisional claim and declare the full taxable gain. The tax will be payable immediately and interest will run from 31 January 2013.

Q. I've received a refund of the PPI premiums I paid on top of my mortgage. Do I need to declare this sum on my tax return?

A. The refund of payment protection insurance (PPI) premiums should not be included on your tax return as it is a repayment of a fee that you were incorrectly charged. However, the bank will have also paid you 8% interest on the PPI refund, and that interest should be declared on your tax return, just as if it was interest paid on a regular savings account. Some banks deducted 20% tax from the interest element of the refund, others did not, so you should check the documents you received with the refund to see if your payment had tax deducted from it or not.

Q. The Taxman has written to me saying I missed a small pension worth about £800 a year from my last tax return. He hasn't noticed that I also missed it off the last four tax returns. What should I do?

A. Best advice is to come clean immediately and tell the Taxman about all the missing amounts of pension income for all tax years. There may not be more tax to pay if the pension provider has already deducted tax at your marginal tax rate. However, if there is higher rate tax to pay there will also be interest due at 3% and possibly a penalty. By confessing all without delay you can qualify for a reduced penalty, down to say 15% of the tax due. We can help you with those penalty negotiations and may be able to get it suspended for up to two years.