Taxation represents the sum of tax currently payable and deferred tax. The company's liability for current tax is calculated using tax rates that have been enacted or substantively enacted by the end of the reporting period. Deferred tax is recognised on all timing differences between the carrying amounts of assets and liabilities in the financial statements and the corresponding tax bases used in the computation of taxable profit. The carrying amount of deferred tax assets is reviewed at the end of each reporting period 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 assets and liabilities are measured at the tax rates that are expected to apply in the period in which the liability is settled or the asset realised, based on tax rates (and tax laws) that have been enacted or substantively enacted by the end of the reporting period.

Stocks are stated at the lower of cost and estimated selling price less costs to complete and sell (net realisable value). Costs, which comprise direct production costs, are based on the method most appropriate to the type of inventory class, but usually on a first-in-first-out basis. Overheads are charged to profit or loss as incurred. Net realisable value is based on the estimated selling price less any estimated completion or selling costs.

When stocks are sold, the carrying amount of those stocks is recognised as an expense in the period in which the related revenue is recognised. The amount of any write-down of stocks to net realisable value and all losses of stocks are recognised as an expense in the period in which the write-down or loss occurs. The amount of any reversal of any write-down of stocks is recognised as a reduction in the amount of stocks recognised as an expense in the period in which the reversal occurs.