by Incredulum on Wed Jul 13, 2011 2:46 pm
3. So you are making a healthy profit on the 10% you rent out.
Anyway, yes, I'm afraid that as this is permanently rented out, you will pay tax on the income as property income(Schedule A), not as trading income. You can deduct 10% of your rent, and presumably 10% (or other sensible amount) of the other costs you mention.
Sorry. You cannot offset b/fwd trading losses against current year property income.
http://www.hmrc.gov.uk/manuals/pimmanual/pim4300.htm allows the treatment of rent as trading income if the letting is a temporary thing only.