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 is reduced for estimated customer returns, rebates and other similar allowances.
When cash inflows are deferred and represent a financing arrangement, the fair value of the consideration is the present value of the future receipts. The difference between the fair value of the consideration and the nominal amount received is recognised as interest income.
Revenue from contracts for the provision of professional services is recognised by reference to the stage of completion when the stage of completion, costs incurred and costs to complete can be estimated reliably. The stage of completion is calculated by comparing costs incurred, mainly in relation to contractual hourly staff rates and materials, as a proportion of total costs. Where the outcome cannot be estimated reliably, revenue is recognised only to the extent of the expenses recognised that it is probable will be recovered.