StocksStocks are stated at the lower of cost and estimated selling price less costs to complete and sell. Cost comprises direct materials and, where applicable, direct labour costs and those overheads that have been incurred in bringing the stocks to their present location and condition.Stocks held for distribution at no or nominal consideration are measured at the lower of replacement cost and cost, adjusted where applicable for any loss of service potential.At each reporting date, an assessment is made for impairment. Any excess of the carrying amount of stocks over its estimated selling price less costs to complete and sell is recognised as an impairment loss in profit or loss. Reversals of impairment losses are also recognised in profit or loss.TaxationThe tax expense represents the sum of the tax currently payable and deferred tax.Current taxThe tax currently payable is based on taxable profit for the year. Taxable profit differs from net profit as reported in the profit and loss account because it excludes items of income or expense that are taxable or deductible in other years and it further excludes items that are never taxable or deductible. The company’s liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the reporting end date.Deferred taxDeferred tax liabilities are generally recognised for all timing differences and deferred tax assets are recognised to the extent that it is probable that they will be recovered against the reversal of deferred tax liabilities or other future taxable profits. Such assets and liabilities are not recognised if the timing difference arises from goodwill or from the initial recognition of other assets and liabilities in a transaction that affects neither the tax profit nor the accounting profit.The carrying amount of deferred tax assets is reviewed at each reporting end date and reduced to the extent that it is no longer probable that sufficient taxable profits will be available to allow all or part of the asset to be recovered. Deferred tax is calculated at the tax rates that are expected to apply in the period when the liability is settled or the asset is realised. Deferred tax is charged or credited in the profit and loss account, except when it relates to items charged or credited directly to equity, in which case the deferred tax is also dealt with in equity. Deferred tax assets and liabilities are offset when the company has a legally enforceable right to offset current tax assets and liabilities and the deferred tax assets and liabilities relate to taxes levied by the same tax authority.