Allowances made against tax for the cost of certain fixed assets such as machinery, plant or IT equipment. Capital allowances can be deducted from profits at a set rate per year and so written it off over a period of time, this is referred to as depreciation.
Small and medium sized business can claim a fixed percentage in the first year on most plant and machinery. Charges may be imposed to take back capital allowances if you sell capital assets for more than the tax written down value.