Turnover is measured at the fair value of the consideration received or receivable, net of discounts and value added taxes. Turnover includes revenue earned from the sale of goods and from the rendering of services. Turnover from the sale of goods is recognised when the significant risks and rewards of ownership of the goods have transferred to the buyer. Turnover from the rendering of services is recognised by reference to the stage of completion of the contract. The stage of completion of a contract is measured by comparing the costs incurred for work performed to date to the total estimated contract costs.

Tangible fixed assets are measured at cost less accumulative depreciation and any accumulative impairment losses. Depreciation is provided on all tangible fixed assets, other than freehold land, at rates calculated to write off the cost, less estimated residual value, of each asset evenly over its expected useful life, as follows: