If my tax relief for buy-to-let were to exceed my income can this be set against other tax liabilities?  Also if one is a higher rate taxpayer and another a basic rate taxpayer, how does one apportion relief?

Arthur Weller Replies:
A regular loss from a UK rental property can only be either a) set off in the same tax year against total income from the taxpayer’s UK rental property business, or b) carried forward to the next tax year where the taxpayer can offset the loss against total income from his UK rental property business. This loss can be carried forward indefinitely until it is used up.
This loss cannot be set against non UK property income.
See http://www.hmrc.gov.uk/manuals/pimmanual/PIM4205.htm.
If two people own a property in partnership, and receive rental income from it, then each will have a separate UK property tax calculation, depending on what proportion of the profits / losses of this property they are entitled to, and what other rental properties they receive profits/losses from.