a.  Change in accounting policy - presentation and disclosure of
 financial statements
 
 The financial statements of the Company have been prepared and
 presented for the year ended March 31, 2012, as per the format
 prescribed under the revised Schedule VI notified under the Companies
 Act, 1956. The adoption of revised Schedule VI does not impact
 recognition and measurement principles followed for the preparation of
 the financial statements. However, it has significant impact on
 presentation and disclosures made in the financial statements. The
 Company has also reclassified the previous year figures in accordance
 with the requirements applicable in the current year.
 
 b.  Use of estimates
 
 The preparation of the financial statements in conformity with
 generally accepted accounting principles requires management to make
 estimates and assumptions that affect the reported amounts of assets
 and liabilities and disclosure of contingent liabilities at the date of
 the financial statements and the results of operations during the
 reporting year end. Although these estimates are based upon
 management''s best knowledge of current events and actions, uncertainty
 about these assumptions and estimates could result in the outcomes
 requiring a material adjustment to the carrying amounts of assets and
 liabilities in future periods.
 
 c.  Tangible assets
 
 Tangible assets are stated at cost of acquisition and subsequent
 improvements thereto, including taxes & duties (net of cenvat credit),
 freight and other incidental expenses related to acquisition and
 installation. Capital work-in-progress is stated at cost.
 
 Site restoration cost obligations are capitalized when it is probable
 that an outflow of resources will be required to settle the obligation
 and a reliable estimate of the amount can be made.
 
 Subsequent costs are included in the asset''s carrying amount or
 recognized as a separate asset, as appropriate, only when it is
 porbable that future economic benefits associated with the item will
 flow to the Company and the cost of the item can be measured realiably.
 All other repair and maintenance costs are recognized in the statement
 of profit and loss as incurred.
 
 Gains and losses arising from retirement or disposal of the tangible
 assets are determined as the difference between the net disposal
 proceeds and the carrying amount of the asset and are recognized in
 statement of profit and loss on the date of retirement and disposal.
 
 d.  Depreciation on tangible assets
 
 Depreciation on tangible assets is provided on the straight line method
 based on useful lives of respective assets as estimated by the
 management or at the rates prescribed under Schedule XIV of the
 Companies Act, 1956, whichever is higher.
 
 The site restoration cost obligation capitalized is depreciated over
 the period of the useful life of the related asset.
 
 Assets costing up to Rs. 5 thousand (other than identified Customer
 Premise Equipment) are being fully depreciated within one year from the
 date of place in service.
 
 e.  Intangible assets
 
 Licenses
 
 The entry fee paid by the Company for cellular and basic circles, upon
 migration to the National Telecom Policy (NTP 1999) and the one time
 license fees paid for acquiring new licences (post NTP 1999) (basic,
 cellular, national long distance and international long distance
 services) has been capitalised as an intangible asset.
 
 The entry fee capitalised is amortised over the period of the license
 and the one time licence fee is amortised over the balance period of
 licence from the date of commencement of commercial operations.
 
 3G spectrum fees are being amortised over the period of license from
 the effective date of launch of 3G services in a circle.  Intangible
 assets under development are valued at cost.
 
 Bandwidth
 
 Bandwidth capacity is amortised on straight line basis over the period
 of the agreement subject to a maximum period of 18 years i.e. estimated
 useful life of bandwidth.
 
 Software
 
 Software is capitalized at the amounts paid to acquire the respective
 license for use and is amortized over the period of license, generally
 not exceeding three years. Software up to Rs. 500 thousand is amortized
 over a period of one year from the date of place in service.
 
 f.  Leases
 
 a) Where the Company is the lessee
 
 Leases where the lessor effectively retains substantially all the risks
 and benefits of ownership of the leased item, are classified as
 operating leases. Lease rentals with respect to assets taken on
 ''Operating Lease'' are charged to the statement of profit and loss on a
 straight-line basis over the lease term.
 
 Leases which effectively transfer to the Company substantially all the
 risks and benefits incidental to ownership of the leased item are
 classified as finance lease. Assets acquired on ''Finance Lease'' which
 transfer risk and rewards of ownership to the Company are capitalized
 as assets by the Company at the lower of fair value of the leased
 property or the present value of the minimum lease payments.
 
 Amortization of capitalised leased assets is computed on the straight
 line method over the useful life of the assets. Lease rental payable is
 apportioned between principal and finance charge using the internal
 rate of return method. The finance charge is allocated over the lease
 term so as to produce a constant periodic rate of interest on the
 remaining balance of liability.
 
 b) Where the Company is the lessor
 
 Leases in which the Company does not transfer substantially all the
 risks and benefits of ownership of the asset are classified as
 operating leases. Lease income in respect of ''Operating Lease'' is
 recognised in the statement of profit and loss on a straight-line basis
 over the lease term. Assets subject to operating leases are included in
 fixed assets.
 
 Leases in which the Company transfer substantially all the risks and
 benefits of ownership of the asset are classified as finance leases.
 
 Assets leased to others under finance lease are recognized as
 receivables at an amount equal to the net investment in the leased
 assets. Finance Income is recognized based on a pattern reflecting a
 constant periodic rate of return on the net investment of the lessor
 outstanding in respect of the lease.
 
 c) Initial direct costs are expensed in the statement of profit and
 loss at the inception of the lease.
 
 g.  Borrowing cost
 
 Borrowing cost attributable to the acquisition or construction of fixed
 assets which takes substantial period of time to get ready for its
 intended use is capitalised as part of the cost of that asset. Other
 borrowing costs are recognised as an expense in the year in which they
 are incurred. The interest cost incurred for funding a qualifying asset
 during the construction period is capitalized based on actual
 investment in the asset at the average interest rate for specific
 borrowings. All other borrowing cost are expensed in the period they
 occur.
 
 h.  Impairment of assets
 
 The carrying amounts of assets are reviewed at each balance sheet date
 for impairment whenever events or changes in circumstances indicate
 that the carrying amount may not be recoverable. An impairment loss is
 recognized for the amount by which the assets'' carrying amount exceeds
 its recoverable amount. The recoverable amount is the higher of the
 assets1 fair value less costs to sell and value in use.
 
 For the purpose of assessing impairment, assets are grouped at the
 lowest levels for which there are separately identifiable cash flows
 (cash generating units).
 
 i.  Asset retirement obligations (ARO)
 
 Provision for ARO is based on past experience and technical estimates.
 
 j. Investment
 
 Current Investments are valued at lower of cost and fair market value
 determined on individual basis.
 
 Non-current investments are valued at cost. Provision is made for
 diminution in value to recognise a decline, if any, other than that of
 temporary nature.
 
 k. Inventory
 
 Inventory is valued at the lower of cost and net realisable value. Cost
 is determined on First in First out basis. Net realisable value is the
 estimated selling price in the ordinary course of business, less
 estimated costs of completion and the estimated costs necessary to make
 the sale.
 
 The Company provides for obsolete and slow-moving inventory based on
 management estimates of the usability of inventory.
 
 l. Revenue recognition and receivables
 
 Mobile Services
 
 Service revenue is recognised on completion of provision of services.
 Service revenue includes income on roaming commission and an access
 charge recovered from other operators, and is net of discounts and
 waivers. Revenue, net of discount, is recognised on transfer of all
 significant risks and rewards to the customer and when no significant
 uncertainty exists regarding realisation of consideration.
 
 Processing fees on recharge is being recognised over the estimated
 customer relationship period or voucher validity period, as applicable.
 
 Revenue from prepaid calling cards packs is recognised on the actual
 usage basis.
 
 Telemedia Services
 
 Service revenue is recognised on completion of provision of services.
 Revenue is recognised when no significant uncertainty exists regarding
 realisation of consideration. Service Revenue includes access charges
 recovered from other operators, and is net of discounts and waivers.
 
 Airtel Business (Previously known as Enterprise Services)
 
 Revenue, net of discount, from sale of goods is recognised on transfer
 of all significant risks and rewards to the customer and when no
 significant uncertainty exists regarding realisation of consideration.
 Revenue on account of bandwidth service is recognised on time
 proportion basis in accordance with the related contracts.
 
 Service Revenue includes access charges recovered from other operators,
 revenues from installation and provision of Internet and Satellite
 Services. Installation charges are recognised as revenue on
 satisfactory completion of installation of hardware and service revenue
 is recognised from the date of satisfactory installation of equipment
 and software at the customer site and provisioning of Internet and
 Satellite Services.
 
 Activation Income
 
 Activation revenue and related direct activation costs, not exceeding
 the activation revenue, are deferred and amortized over the related
 estimated customer relationship period, as derived from the estimated
 customer churn period.
 
 Investing and Other Activities
 
 Income on account of interest and other activities are recognised on an
 accrual basis. Dividends are accounted for when the right to receive
 the payment is established.
 
 Provision for Doubtful Debts
 
 The Company provides for amounts outstanding for more than 90 days in
 case of active subscribers, roaming receivables, receivables for data
 services and for entire outstanding from deactivated customers net off
 security deposits or in specific cases where the management is of the
 view that the amounts from certain customers are not recoverable.
 
 For receivables due from the other operators on account of their
 National Long Distance (NLD) and International Long Distance (ILD)
 traffic for voice and Interconnect Usage Charges (IUC), the Company
 provides for amounts outstanding for more than 120 days from the date
 of billing, net of any amounts payable to the operators or in specific
 cases where management is of the view that the amounts from these
 operators are not recoverable.
 
 Accrued Billing Revenue
 
 Accrued billing revenue represent revenue recognized in respect of
 Mobile, Broadband and Telephone, and Long Distance services provided
 from the bill cycle date to the end of each month. These are billed in
 subsequent periods as per the terms of the billing plans.
 
 m. License fees - revenue share
 
 With effect from August 1, 1999, the variable licence fee computed at
 prescribed rates of revenue share is charged to the statement of profit
 and loss in the year in which the related revenues are recognised.
 Revenue for this purpose is identified as adjusted gross revenue as per
 the respective license agreements.
 
 n. Foreign currency translation, accounting for forward contracts and
 derivatives
 
 Initial Recognition
 
 Foreign currency transactions are recorded in the reporting currency,
 by applying to the foreign currency amount the exchange rate between
 the reporting currency and the foreign currency at the date of the
 transaction.
 
 Conversion
 
 Foreign currency monetary items are reported using the closing rate.
 Non-monetary items which are carried in terms of historical cost
 denominated in a foreign currency are reported using the exchange rate
 at the date of the transaction; and non-monetary items which are
 carried at fair value or other similar valuation denominated in a
 foreign currency are reported using the exchange rates that existed
 when the values were determined.
 
 Exchange Differences
 
 Exchange differences arising on the settlement of monetary items or on
 restatement of the Company''s monetary items at rates different from
 those at which they were initially recorded during the year, or
 reported in previous financial statements, are recognized as income or
 as expenses in the year in which they arise as mentioned below.
 
 Forward Exchange Contracts covered under AS 11, ''The Effects of Changes
 in Foreign Exchange Rates''
 
 Exchange differences on forward exchange contracts and plain vanilla
 currency options for establishing the amount of reporting currency and
 not intended for trading & speculation purposes, are recognised in the
 statement of profit and loss in the year in the which the exchange rate
 changes. The premium or discount arising at the inception of forward
 exchange contracts is amortised as expense or income over the life of
 the contract. Any profit or loss arising on cancellation or renewal of
 such forward exchange contract is recognised as income or expense for
 the year.
 
 Exchange difference on forward contracts which are taken to establish
 the amount other than the reporting currency arising due to the
 difference between forward rate available at the reporting date for the
 remaining maturity period and the contracted forward rate (or the
 forward rate last used to measure a gain or loss on the contract for an
 earlier period) are recognised in the statement of profit and loss for
 the year.
 
 Other Derivative Instruments, not in the nature of AS 11, ''The Effects
 of Changes in Foreign Exchange Rates''
 
 The Company enters into various foreign currency option contracts and
 interest rate swap contracts that are not in the nature of forward
 contracts designated under AS 11 as such and contracts that are not
 entered to establish the amount of the reporting currency required or
 available at the settlement date of a transaction; to hedge its risks
 with respect to foreign currency fluctuations and interest rate
 exposure arising out of import of capital goods using foreign currency
 loan.  In accordance with the ICAI announcement, at every year end, all
 outstanding derivative contracts are fair valued on a mark-to-market
 basis and any loss on valuation is recognised in the statement of
 profit and loss, on each contract basis.  Any gain on mark-to-market
 valuation on respective contracts is not recognized by the Company,
 keeping in view the principle of prudence as enunciated in AS 1,
 ''Disclosure of Accounting Policies''. Any reduction to fair values and
 any reversals of such reductions are included in profit and loss
 statement of the year.
 
 Embedded Derivative Instruments
 
 The Company occasionally enters into contracts that do not in their
 entirety meet the definition of a derivative instrument that may
 contain embedded derivative instruments - implicit or explicit terms
 that affect some or all of the cash flow or the value of other
 exchanges required by the contract in a manner similar to a derivative
 instrument. The Company assesses whether the economic characteristics
 and risks of the embedded derivative are clearly and closely related to
 the economic characteristics and risks of the remaining component of
 the host contract and whether a separate, non-embedded instrument with
 the same terms as the embedded instrument would meet the definition of
 a derivative instrument. When it is determined that (1) the embedded
 derivative possesses economic characteristics and risks that are not
 clearly and closely related to the economic characteristics and risks
 of the host contract and (2) a separate, stand-alone instrument with
 the same terms would qualify as a derivative instrument, the embedded
 derivative is separated from the host contract, carried at fair value
 as a trading or non-hedging derivative instrument. At every year end,
 all outstanding embedded derivative instruments are fair valued on
 mark-to-market basis and any loss on valuation is recognized in the
 statement of profit and loss for the year. Any reduction in mark to
 market valuations and reversals of such reductions are included in
 profit and loss statement of the year.
 
 Translation of Integral and Non-Integral Foreign Operation
 
 The financial statements of an integral foreign operation are
 translated as if the transactions of the foreign operation have been
 those of the Company itself.
 
 In translating the financial statements of a non-integral foreign
 operation for incorporation in financial statements, the assets and
 liabilities, both monetary and non-monetary are translated at the
 closing rate; income and expense items are translated at exchange rate
 at the date of transaction for the year; and all resulting exchange
 differences are accumulated in a foreign currency translation reserve
 until the disposal of the net investment.
 
 Foreign exchange contracts for trading and speculation purpose
 
 Foreign exchange contracts intended for trading and/or speculation are
 fair valued on a mark-to-market basis and any gain or loss on such
 valuation is recognised in the statement of profit and loss for the
 year.
 
 o.  Employee benefits
 
 (a) Short term employee benefits are recognised in the year during
 which the services have been rendered.
 
 (b) All employees of the Company are entitled to receive benefits under
 the Provident Fund, which is a defined contribution plan. Both the
 employee and the employer make monthly contributions to the plan at a
 predetermined rate (presently 12%) of the employees'' basic salary.
 These contributions are made to the fund administered and managed by
 the Government of India. In addition, some employees of the Company are
 covered under the employees'' state insurance schemes, which are also
 defined contribution schemes recognized and administered by the
 Government of India.
 
 The Company''s contributions to both these schemes are expensed in the
 statement of profit and loss. The Company has no further obligations
 under these plans beyond its monthly contributions.
 
 (c) Some employees of the Company are entitled to superannuation, a
 defined contribution plan which is administered through Life Insurance
 Corporation of India (LIC). Superannuation benefits are recorded as
 an expense as incurred.
 
 (d) The compensated absences are provided for based on actuarial
 valuation. The actuarial valuation is done as per projected unit credit
 method at the end of each year.
 
 (e) The Company provides for gratuity obligations through a defined
 benefit retirement plan (the ''Gratuity Plan'') covering all employees.
 The Gratuity Plan provides a lump sum payment to vested employees at
 retirement or termination of employment based on the respective
 employee salary and years of employment with the Company. The Company
 provides for the Gratuity Plan based on actuarial valuations as per the
 Projected Unit Credit Method at the end of each year in accordance with
 Accounting Standard 15, Employee Benefits. The Company makes annual
 contributions to the LIC for the Gratuity Plan in respect of employees
 at certain circles.
 
 (f) Other long term employee benefits are provided based on actuarial
 valuation made at the end of each year. The actuarial valuation is done
 as per projected unit credit method.
 
 (g) Actuarial gains and losses are recognized as and when incurred.
 
 p. Pre-operative expenditure
 
 Expenditure incurred by the Company from the date of acquisition of
 license for a new circle or from the date of start-up of new venture or
 business, up to the date of commencement of commercial operations of
 the circle or the new venture or business, not directly attributable to
 fixed assets are charged to the statement of profit and loss in the
 year in which such expenditure is incurred.
 
 q. Taxes
 
 Current Income Tax
 
 Current Income Tax is measured at the amount expected to be paid to the
 tax authorities in accordance with Indian Income Tax Act, 1961.
 
 Deferred Tax
 
 Deferred income taxes reflects the impact of current year timing
 differences between taxable income and accounting income for the year
 and reversal of timing differences of earlier years. Deferred tax is
 measured based on the tax rates and the tax laws enacted or
 substantively enacted at the balance sheet date. Deferred tax assets
 are recognised and reviewed at each balance sheet date, only to the
 extent that there is reasonable certainty that sufficient future
 taxable income will be available against which such deferred tax assets
 can be realised. In situations, where the Company has unabsorbed
 depreciation or carry forward tax losses, all deferred tax assets are
 recognised only if there is virtual certainty supported by convincing
 evidence that they can be realised against future taxable profits. At
 each balance sheet date, unrecognised deferred tax assets of earlier
 years are re-assessed and recognised to the extent that it has become
 reasonably or virtually certain, as the case may be, that future
 taxable income will be available against which such deferred tax assets
 can be realized.
 
 MAT Credit
 
 Minimum Alternative Tax (MAT) credit is recognised as an asset only
 when and to the extent there is convincing evidence that the Company
 will pay normal income tax during the specified period. In the year in
 which the MAT credit becomes eligible to be recognized as an asset in
 accordance with the recommendations contained in Guidance Note issued
 by the ICAI, the said asset is created by way of a credit to the
 statement of profit and loss account and shown as MAT Credit
 Entitlement. The Company reviews the same at each balance sheet date
 and writes down the carrying amount of MAT Credit Entitlement to the
 extent there is no longer convincing evidence to the effect that
 Company will pay normal income tax during the specified period.
 
 r. Share based compensation
 
 Employee stock compensation are valued using Black Scholes/Monte
 Carlo/Lattice valuation option - pricing model and the fair value is
 recognised as an expense over the period in which the options vest. The
 difference between the actual purchase cost of shares issued upon
 exercise of options and the sum of fair value of the option and
 exercise price is adjusted against General Reserve.
 
 s. Segmental reporting
 
 a) Primary Segment
 
 The Company operates in three primary business segments viz. Mobile
 Services, Telemedia Services and Airtel Business.
 
 b) Secondary Segment
 
 The Company has operations serving customers within India as well as in
 other countries located outside India. The operations in India
 constitute the major part, which is the only reportable segment, the
 remaining portion being attributable to others.
 
 t. Earnings per share
 
 The earnings considered in ascertaining the Company''s Earnings Per
 Share (''EPS'') comprise the net profit after tax attributable to equity
 shareholders. The number of shares used in computing basic EPS is the
 weighted average number of shares outstanding during the year. The
 weighted average number of equity shares outstanding during the year is
 adjusted for events of share splits/bonus issue post year end and
 accordingly, the EPS is restated for all periods presented in these
 financial statements. The diluted EPS is calculated on the same basis
 as basic EPS, after adjusting for the effects of potential dilutive
 equity shares unless impact is anti dilutive.
 
 The weighted average number of equity shares outstanding during the
 year are adjusted for events of bonus issue; bonus element in a rights
 issue to existing shareholders; share split; and reverse share split
 (consolidation of shares).
 
 u.  Provisions and contingencies
 
 Provisions are recognised when the Company has a present obligation as
 a result of past event; it is more likely than not that an outflow of
 resources will be required to settle the obligation, in respect of
 which a reliable estimate can be made.  Provisions are not discounted
 to its present value and are determined based on best estimate required
 to settle the obligation at the balance sheet date. These are reviewed
 at each balance sheet date and adjusted to reflect the current best
 estimates.
 
 A contingent liability is a possible obligation that arises from past
 events whose existence will be confirmed by the occurrence or
 non-occurrence of one or more uncertain future events not wholly within
 the control of the Company or a present obligation that is not
 recognized because it is not probable that an outflow of resources
 embodying economic benefits will be required to settle the obligation
 or the amount of the obligation cannot be measured with sufficient
 reliability. Information on contingent liabilities is disclosed in the
 notes to the financial statements, unless the possibility of an outflow
 of resources embodying economic benefits is remote.
 
 v. Multiple element contracts with vendors
 
 The Company enters into multiple element contracts with vendors for
 supply of goods and rendering of services. The consideration under this
 contracts is/may be determined independent of the value of supplies
 received and services availed. Accordingly, the supplies and services
 are accounted for based on their relative fair values to the overall
 consideration. The supplies with finite life under such contracts are
 accounted under as Tangible assets or as Intangible assets in view of
 the substance of these contracts and existence of economic ownership in
 these assets.
 
 w. Cash and cash equivalents
 
 Cash and cash equivalents for the purpose of cash flow statement
 comprise cash in hand and at bank and short-term investments with an
 original maturity of three months or less.