Current tax represents the amount of tax payable or receivable in respect of the taxable profit (or loss) for the current or past reporting periods. It is measured at the amount expected to be paid or recovered using the tax rates and laws that have been enacted or substantively enacted by the balance sheet date.Deferred tax is recognised in respect of all timing differences that have originated but not reversed at the balance sheet date, where material.Deferred tax assets are only 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.Deferred tax is measured using the tax rates and laws that have been enacted or substantively enacted by the balance sheet date that are expected to apply to the reversal of timing differences. Deferred tax on revalued non-depreciable tangible fixed assets and investment properties is measured using the rates and allowances that apply to the sale of the asset.Short term debtors are measured at transaction value less any impairment. At each balance sheet date, debtors are assessed for objective evidence of impairment. If an asset is impaired, the impairment loss is measured as the difference between the carrying amount and the amount expected to be received.Short term creditors are measured at transaction value.