The tax expense represents the sum of the tax currently payable and deferred tax.

Current taxation

The tax currently payable is based on taxable profit for the year. Taxable profit differs from net profit as reported in the income statement 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.

Any tangible assets carried at a revalued amount are recorded at the fair value at the date of revaluation less any subsequent accumulated depreciation and subsequent accumulated impairment losses.

An increase in the carrying amount of an asset as a result of a revaluation is recognised in other comprehensive income and accumulated in capital and reserves. However, the increase is recognised in profit or loss to the extent that it reverses a revaluation decrease of the same asset previously recognised in profit or loss. A decrease in the carrying amount of an asset as a result of revaluation is recognised in other comprehensive income to the extent of any previously recognised revaluation increase accumulated in capital and reserves. If a revaluation decrease exceeds the accumulated revaluation gains accumulated capital and reserves in respect of that asset, the excess is recognised in profit or loss.

Depreciation is recognised so as to write off the cost or valuation of assets less their residual values over the useful lives on the following basis:

Provisions are initially measured at the best estimate of the amount required to settle the obligation at the reporting date and subsequently reviewed at each reporting date and adjusted to reflect the current best estimate of the amount that would be required to settle the obligation. Any adjustments to the amounts previously recognised are recognised in profit or loss unless the provision was originally recognised as part of the cost of an asset. When a provision is measured at the present value of the amount expected to be required to settle the obligation, the unwinding of the discount is recognised in finance costs in profit or loss in the period it arises.