The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenditure during the reporting period. Actual results could differ from those estimates. Estimates are used principally when accounting for interconnect income, provision for doubtful debts, payments to telecommunication operators, depreciation, goodwill amortisation and impairment, employee pension schemes and taxes.

II Turnover
Group turnover, which excludes value added tax and other sales taxes, comprises the value of services provided and equipment sales by group undertakings, excluding those between them.

Total turnover is group turnover together with the group's share of its associates' and joint ventures' turnover, excluding the group's share of transactions between the group and its principal joint venture, Concert BV.

Turnover from calls is recognised in the group profit and loss account at the time the call is made over the group's networks. Turnover from rentals is recognised evenly over the period to which the charges relate. Turnover from sales is recognised at the point of sale. Prepaid call card sales are deferred until the customer uses the stored value in the card to pay for the relevant calls. Turnover arising from the provision of other services, including maintenance contracts, is recognised evenly over the periods in which the service is provided to the customer. Turnover from installation and connection activities is recognised in the same period as the related costs. Turnover from classified directories, mainly comprising advertising revenue, is recognised in the group profit and loss account upon completion of delivery.

III Research and development
Expenditure on research and development is written off as incurred.

IV Leases
Operating lease rentals are charged against the profit and loss account on a straight-line basis over the lease period except where the contractual payment terms are considered to be a more systematic and appropriate basis.

V Interest
Interest payable, including that related to financing the construction of tangible fixed assets, is written off as incurred. Discounts or premiums and expenses on the issue of debt securities are amortised over the term of the related security and included within interest payable. Premiums payable on early redemptions of debt securities, in lieu of future interest costs, are written off when paid.

VI Foreign currencies
On consolidation, assets and liabilities of foreign undertakings are translated into sterling at year end exchange rates. The results of foreign undertakings are translated into sterling at average rates of exchange for the year.

Exchange differences arising from the retranslation at year end exchange rates of the net investment in foreign undertakings, less exchange differences on borrowings which finance or provide a hedge against those undertakings, are taken to reserves and are reported in the statement of total recognised gains and losses.

All other exchange gains or losses are dealt with through the profit and loss account.

VII Intangibles
(a) Goodwill
Goodwill, arising from the purchase of subsidiary undertakings and interests in associates and joint ventures, represents the excess of the fair value of the purchase consideration over the fair value of the net assets acquired.

For acquisitions completed on or after 1 April 1998, the goodwill arising is capitalised as an intangible asset or, if arising in respect of an associate or joint venture, recorded as part of the related investment. Goodwill is amortised on a straight line basis from the time of acquisition over its useful economic life. The economic life is normally presumed to be a maximum of 20 years.

For acquisitions on or before 31 March 1998, the goodwill is written off on acquisition against group reserves.

If an undertaking is subsequently divested, the appropriate unamortised goodwill or goodwill written off to reserves is dealt with through the profit and loss account in the period of disposal as part of the gain or loss on divestment.

(b) Other intangibles
Licence fees paid to governments, which permit telecommunication activities to be operated for defined periods, are amortised from the later of the start of the licence period or launch of service to the end of the licence period on a straight-line basis.

VIII Tangible fixed assets
Tangible fixed assets are stated at historical cost less depreciation.

(a) Cost
Cost in the case of network services includes contractors' charges and payments on account, materials, direct labour and directly attributable overheads.

(b) Depreciation
Depreciation is provided on tangible fixed assets on a straight line basis from the time they are available for use, so as to write off their costs over their estimated useful lives taking into account any expected residual values. No depreciation is provided on freehold land.

The lives assigned to other significant tangible fixed assets are:

Freehold buildings -	40 years
Leasehold land and buildings -	Unexpired portion of lease or 40 years, whichever is the shorter
Transmission equipment:
duct -	25 years
cable -	3 to 25 years
radio and repeater equipment -	2 to 25 years
Exchange equipment -	2 to 13 years
Computers and office equipment -	2 to 6 years
Payphones, other network equipment, motor vehicles and cableships -	2 to 20 years

IX Fixed asset investments
Investments in subsidiary undertakings, associates and joint ventures are stated in the balance sheet of the company at cost less amounts written off. Amounts denominated in foreign currency are translated into sterling at year end exchange rates.

Investments in associates and joint ventures are stated in the group balance sheet at the group's share of their net assets, together with any attributable unamortised goodwill on acquisitions arising on or after 1 April 1998.

The group's share of profits less losses of associates and joint ventures is included in the group profit and loss account.

Investments in other participating interests and other investments are stated at cost less amounts written off.

X Asset impairment
Intangible and tangible fixed assets are tested for impairment when an event that might affect asset values has occurred. Goodwill is also reviewed for impairment at the end of the first financial year after acquisition.

An impairment loss is recognised to the extent that the carrying amount cannot be recovered either by selling the asset or by the discounted future cash flows from operating the assets.

XI Stocks
Stocks mainly comprise items of equipment, held for sale or rental, consumable items and work in progress on long-term contracts.

Equipment held and consumable items are stated at the lower of cost and estimated net realisable value, after provisions for obsolescence.

Work in progress on long-term contracts is stated at cost, after deducting payments on account, less provisions for any foreseeable losses.

XII Debtors
Debtors are stated in the balance sheet at estimated net realisable value. Net realisable value is the invoiced amount less provisions for bad and doubtful debtors. Provisions are made specifically against debtors where there is evidence of a dispute or an inability to pay. An additional provision is made based on an analysis of balances by age, previous losses experienced and general economic conditions.

XIII Redundancy costs
Redundancy or leaver costs arising from periodic reviews of staff levels are charged against profit in the year in which the group is demonstrably committed to the employees leaving the group.

If the estimated cost of providing incremental pension benefits in respect of employees leaving the group exceeds the total accounting surplus based on the latest actuarial valuation of the group's pension scheme and the amount of the provision for pension liabilities on the balance sheet, then the excess estimated costs are charged against profit in the year in which the employees agree to leave the group, within redundancy or leaver costs.

XIV Pension schemes
The group operates funded defined benefit pension schemes, which are independent of the group's finances, for the substantial majority of its employees. Actuarial valuations of the main scheme are carried out as determined by the trustees at intervals of not more than three years, the rates of contribution payable and the pension cost being determined on the advice of the actuaries, having regard to the results of these valuations. In any intervening years, the actuaries review the continuing appropriateness of the contribution rates.

The cost of providing pensions is charged against profits over employees' working lives with the group using the projected unit method. Variations from this regular cost are allocated on a straight-line basis over the average remaining service lives of current employees to the extent that these variations do not relate to the estimated cost of providing incremental pension benefits in the circumstances described in XIII above.

Interest is accounted for on the provision in the balance sheet which results from differences between amounts recognised as pension costs and amounts funded. The regular pension cost, variations from the regular pension cost, described above, and interest are all charged within staff costs.

The group also operates defined contribution pension schemes and the profit and loss account is charged with the contributions payable.

XV Taxation
The group has adopted Financial Reporting Standard 19 "Deferred Taxation" (FRS 19) during the 2002 financial year.

Full provision is made for deferred taxation on all timing differences which have arisen but have not reversed at the balance sheet date.

Prior to the adoption of FRS 19, the group provided for deferred taxation only to the extent that timing differences were expected to reverse in the foreseeable future. The adoption of the new policy has been made by way of a prior year adjustment to previously published results as though the revised policy had always been applied by the group.

XVI Financial instruments
(a) Debt instruments
Debt instruments are stated at the amount of net proceeds adjusted to amortise any discount evenly over the term of the debt, and further adjusted for the effect of currency swaps acting as hedges.

(b) Derivative financial instruments
The group uses derivative financial instruments to reduce exposure to foreign exchange risks and interest rate movements. The group does not hold or issue derivative financial instruments for financial trading purposes.

Criteria to qualify for hedge accounting
The group considers its derivative financial instruments to be hedges when certain criteria are met. For foreign currency derivatives, the instrument must be related to actual foreign currency assets or liabilities or a probable commitment and whose characteristics have been identified. It must involve the same currency or similar currencies as the hedged item and must also reduce the risk of foreign currency exchange movements on the group's operations. For interest rate derivatives, the instrument must be related to assets or liabilities or a probable commitment, such as a future bond issue, and must also change the interest rate or the nature of the interest rate by converting a fixed rate to a variable rate or vice versa.

Accounting for derivative financial instruments
Principal amounts underlying currency swaps are revalued at exchange rates ruling at the date of the group balance sheet and, to the extent that they are not related to debt instruments, are included in debtors or creditors.

Interest differentials, under interest rate swap agreements used to vary the amounts and periods for which interest rates on borrowings are fixed, are recognised by adjustment of interest payable.

The forward exchange contracts used to change the currency mix of net debt are revalued to balance sheet rates with net unrealised gains and losses being shown as part of debtors, creditors, or as part of net debt. The difference between spot and forward rate for these contracts is recognised as part of net interest payable over the term of the contract.

The forward exchange contracts hedging transaction exposures are revalued at the prevailing forward rate on the balance sheet date with net unrealised gains and losses being shown as debtors and creditors.

Instruments that form hedges against future fixed-rate bond issues are marked to market. Gains or losses are deferred until the bond is issued when they are recognised evenly over the term of the bond.