When you buy a fixed asset you can off set the cost of this asset against your profits by claiming capital allowances.
There are varying rated of capital allowances ranging from 4% for buildings to 100% annual investment allowance.
The annual investment allowance was introduced in April 2008. This allows the first £50,000 of qualifying capital expenditure to be written off against profits in the year in which the cost was incurred.
Capital allowances are a complex area. Often the services of an accountant are needed to work out the capital allowances.