I have bought many of the books about property tax, including ‘How to avoid landlord taxes 2013/14’, and read about HMRC’s Business Income manual at BIM45700. My strategy is to buy a property, do it up, buy another and rent out my old house. I have done this three times but now I want to stay where I am and just buy the fourth property with cash without borrowing at a high interest rate just to get tax relief, but use the interest relief from my residential property. I questioned HMRC via telephone about the use of unclaimed interest relief from my residential property to fund a buy-to-let property at the start of the rental business and they said no. When I called this year after reading your book, they said, “Ah yes, you are right but you need to request”. I understand I can only go back four years to restate despite their incorrect advice. What do you suggest – should I go back and correct from the 2002/03 error or the last four years and correct in this year’s return or else write to them and ask for a restatement and a ruling? I am sure many are in this same situation. Due to the high repair costs I have only accumulated tax losses so there is no refund of tax to be paid to me. The unclaimed interest will just increase my accumulated losses. 

Overpayment relief allows a claim to be made within four years after the end of the relevant tax year. So that means that currently you can only go back to tax year 2010/11. See www.hmrc.gov.uk/manuals/sacmanual/SACM12150.htm on how to make your claim, it is not made through the self-assessment return form (SA100) or equivalent. See HMRC’s Self-Assessment Claims manual at SACM12057 there "Understated losses can be the subject of an overpayment relief claim if they have created an overpayment of tax."