Impairment of fixed assets A review for indicators of impairment is carried out at each reporting date, with the recoverable amount being estimated where such indicators exist. Where the carrying value exceeds the recoverable amount, the asset is impaired accordingly. Prior impairments are also reviewed for possible reversal at each reporting date. For the purposes of impairment testing, when it is not possible to estimate the recoverable amount of an individual asset, an estimate is made of the recoverable amount of the cash-generating unit to which the asset belongs. Investments Fixed asset investments are initially recorded at cost, and subsequently stated at cost less any accumulated impairment losses. Listed investments are measured at fair value with changes in fair value being recognised in profit or loss. Debtors Short term debtors are measured at transaction price (which is usually the invoice price), less any impairment losses for bad and doubtful debts. Loans and other financial assets are initially recognised at transaction price including any transaction costs and subsequently measured at amortised cost determined using the effective interest method, less any impairment losses for bad and doubtful debts. Creditors Short term creditors are measured at transaction price (which is usually the invoice price). Loans and other financial liabilities are initially recognised at transaction price net of any transaction costs and subsequently measured at amortised cost determined using the effective interest method. Taxation A current tax liability is recognised for the tax payable on the taxable profit of the current and past periods. A current tax asset is recognised in respect of a tax loss that can be carried back to recover tax paid in a previous period. Deferred tax is recognised in respect of all timing differences between the recognition of income and expenses in the financial statements and their inclusion in tax assessments. Unrelieved tax losses and other deferred tax assets are recognised only 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 reporting date and that are expected to apply to the reversal of the timing difference, except for revalued land and investment property where the tax rate that applies to the sale of the asset is used. Current and deferred tax assets and liabilities are not discounted. Financial instruments Financial liabilities and equity instruments are classified according to the substance of the contractual arrangements entered into. An equity instrument is any contract that evidences a residual interest in the assets of the entity after deducting all of its financial liabilities. Foreign currency translation Transactions in foreign currencies are initially recognised at the rate of exchange ruling at the date of the transaction. At the end of each reporting period foreign currency monetary items are translated at the closing rate of exchange. Non-monetary items that are measured at historical cost are translated at the rate ruling at the date of the transaction. All differences are charged to profit or loss.