In reply to estivoautumnal:
The loss for tax purposes will not necessarily be calculated as incomes less expenditure if some of the expenditure is on equipment which should be treated as fixed assets for ongoing use in the business.
For fixed assets you would typically only be able to expense a certain amount of the cost in each year, based on capital allowances rates (see
http://www.hmrc.gov.uk/capital-allowances/basics.htm). For certain categories of assets you are able to charge the full expense in the year of acquisition (called first year allowances - see
http://www.hmrc.gov.uk/capital-allowances/fya/basics.htm). However, there's also an Annual Investment Allowance (see
http://www.hmrc.gov.uk/capital-allowances/plant.htm) which, depending on how much you've spent, may mean you could expense all of your costs and then carry forward any residual losses.
Depending on how much you've spent and on what, this may mean that, for tax purposes, you haven't actually made a loss (which may be a good or bad thing, depending how you look at it!).
The HMRC website actually has quite a lot of good guidance, but tax can be a bit of a minefield...
OM