Cash and cash equivalents Cash at bank and in hand are basic financial assets and include cash in hand, deposits held at call with banks, other short-term liquid investments with original maturities of three months or less, and bank overdrafts. Bank overdrafts are shown within borrowings in current liabilities. Taxation The charge for taxation is the sum of the tax currently payable and deferred tax payable. Current tax is measured at amounts expected to be paid using the tax rates and laws that have been enacted or substantively enacted by the reporting period end date. Tax credits in respect of Research & Development Tax Relief are recognised when it is considered probable the amount will be received. Deferred tax balances are recognised in respect of all timing differences that have originated but not reversed by the period end reporting date except that the recognition of deferred tax assets is limited to the extent that the group anticipates making sufficient taxable profits in the future to absorb the reversal of the underlying differences. Leases Rentals payable under operating leases, including any lease incentives received, are charged to income on a straight-line basis over the term of the relevant lease except where another more systematic basis is more representative of the time pattern in which economic benefits from the lease asset are consumed. Foreign exchange Transactions in currencies other than pounds sterling are recorded at the rates of exchange prevailing at the dates of the transactions. At each reporting end date, monetary assets and liabilities that are denominated in foreign currencies are retranslated at the rates prevailing on the reporting end date. Gains and losses arising on translation are included in the consolidated statement of comprehensive income for the year. Financial liabilities Financial liabilities are classified as either financial liabilities at fair value through profit or loss or other financial liabilities. Financial liabilities are stated at fair value with differences taken to the consolidated statement of comprehensive income. Interest on financial liabilities up to maturity is included in the finance costs line item in the consolidated statement of comprehensive income. Other financial liabilities are initially measured at fair value, net of transaction costs. For convertible loan notes, the amount initially attributed to the debt component is at fair value, net of transaction costs and the conversion and redemption features are measured at fair value through profit or loss.