Corporation tax 2018/19 2017/18 Corporation taxThis calculator uses the 2018/19 corporation tax rates to work out your liability. This may not be an accurate reflection of your corporation tax liability, please contact us to discuss further.Company details Net trading profit for the year (£): * The net trading profit was after charging depreciation of (£): * Capital assets (excluding cars) purchased in the year (£): * e.g. Plant and machinery. Not property, goodwill etc. Corporation tax is normally payable 9 months and 1 day after the end of your financial year. Depreciation is one of those items in your profit and loss account that is not an allowable cost for corporation tax purposes. Tax relief is available for certain capital expenditure. This calculator only allows for capital expenditure incurred during the year you are looking at. There is a £200,000 annual investment allowance for plant and machinery. Contact us to discuss tax relief on capital expenditure. Please note that the results you see on your screen are estimates only. If you wish us to look further you will need to contact us.