8.1 Critical accounting estimates

TELUS' significant accounting policies are described in Note 1 of the Consolidated financial statements. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions. Management's estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The Company's critical accounting estimates are described below and are generally discussed with the Audit Committee each quarter.

General

• Unless otherwise specified in the discussion of the specific critical accounting estimates, the Company is not aware of trends, commitments, events or uncertainties that it reasonably expects to materially affect the methodology or assumptions associated with the critical accounting estimates, subject to the items identified in the Forward-looking statements section of this Management's discussion and analysis.
• In the normal course, changes are made to assumptions underlying all critical accounting estimates to reflect current economic conditions, updating of historical information used to develop the assumptions and changes in the Company's debt ratings, where applicable. Unless otherwise specified in the discussion of the specific critical accounting estimates, it is expected that no material changes in overall financial performance and financial statement line items would arise either from reasonably likely changes in material assumptions underlying the estimate or from selection of a different estimate from within a valid range of estimates.
• All critical accounting estimates are uncertain at the time of making the estimate and affect the following Consolidated income statement line items: income taxes (except for estimates about goodwill) and Net income. Similarly, all critical accounting estimates affect the following Consolidated balance sheet line items: current assets (income and other taxes receivable); current liabilities (income and other taxes payable); future income tax liabilities; and shareholders' equity (retained earnings). Generally, the discussion of each critical accounting estimate does not differ between the Company's two segments: wireline and wireless. The critical accounting estimates affect the Consolidated income statement and Consolidated balance sheet line items as follows:

Accounts receivable

General

• The Company considers the business area that gave rise to the accounts receivable, performs statistical analysis of portfolio delinquency trends and performs specific account identification when determining its allowance for doubtful accounts. This information is also used in conjunction with current market-based rates of borrowing to determine the fair value of its residual cash flows arising from accounts receivable securitization. The fair value of the Company's residual cash flows arising from the accounts receivable securitization is also referred to as its "retained interest."
• Assumptions underlying the allowance for doubtful accounts include portfolio delinquency trends and specific account assessments made when performing specific account identification. Assumptions underlying the determination of the fair value of residual cash flows arising from accounts receivable securitization include those developed when determining the allowance for doubtful accounts as well as the effective annual discount rate.
• These accounting estimates are in respect of the Accounts receivable line item on the Company's Consolidated balance sheet comprising approximately 4% of total assets as at December 31, 2006. If the future were to adversely differ from management's best estimates of the fair value of the residual cash flows and the allowance for doubtful accounts, the Company could experience a bad debt charge in the future. Such a bad debt charge does not result in a cash outflow.

Key economic assumptions used to determine the fair value of residual cash flows arising from accounts receivable securitization

• The estimate of the Company's fair value of its retained interest could materially change from period to period due to the fair value estimate being a function of the amount of accounts receivable sold, which can vary on a monthly basis. See Note 13 of the Consolidated financial statements for further analysis.

The allowance for doubtful accounts

• The estimate of the Company's allowance for doubtful accounts could materially change from period to period due to the allowance being a function of the balance and composition of accounts receivable, which can vary on a month-to-month basis. The variance in the balance of accounts receivable can arise from a variance in the amount and composition of operating revenues, from a variance in the amount of accounts receivable sold to the securitization trust and from variances in accounts receivable collection performance.

Inventories

The allowance for inventory obsolescence

• The Company determines its allowance for inventory obsolescence based upon expected inventory turnover, inventory aging, and current and future expectations with respect to product offerings.
• Assumptions underlying the allowance for inventory obsolescence include future sales trends and offerings and the expected inventory requirements and inventory composition necessary to support these future sales offerings. The estimate of the Company's allowance for inventory obsolescence could materially change from period to period due to changes in product offerings and consumer acceptance of those products.
• This accounting estimate is in respect of the Inventory line item on the Company's Consolidated balance sheet, which comprises approximately 1% of total assets as at December 31, 2006. If the allowance for inventory obsolescence was inadequate, the Company could experience a charge to operations expense in the future. Such an inventory obsolescence charge does not result in a cash outflow.

Capital assets and Goodwill

General

• The accounting estimates for Capital assets and Goodwill represent approximately 67% and 19%, respectively, of TELUS' Consolidated balance sheet, as at December 31, 2006. If TELUS' estimated useful lives of assets were incorrect, it could experience increased or decreased charges for amortization of intangible assets or depreciation in the future. If the future were to adversely differ from management's best estimate of key economic assumptions and associated cash flows were to materially decrease, the Company could potentially experience future material impairment charges in respect of its capital assets, including intangible assets with indefinite lives and goodwill. If intangible assets with indefinite lives were determined to have finite lives at some point in the future, the Company could experience increased charges for amortization of intangible assets. Such charges do not result in a cash outflow and of themselves would not affect the Company's immediate liquidity.

The estimated useful lives of assets; the recoverability of tangible assets

• The estimated useful lives of assets are determined by a continuing program of asset life studies. The recoverability of tangible assets is significantly impacted by the estimated useful lives of assets.
• Assumptions underlying the estimated useful lives of assets include timing of technological obsolescence, competitive pressures and future infrastructure utilization plans.

The recoverability of intangible assets with indefinite lives; the recoverability of goodwill

• Consistent with current industry-specific valuation methods, the Company uses a discounted cash flow model combined with a market-based approach in determining the fair value of its spectrum licences and goodwill. See Note 14(c) of the Consolidated financial statements for further discussion of methodology.
• The most significant assumptions underlying the recoverability of intangible assets with indefinite lives and goodwill include: future cash flow and growth projections including economic risk assumptions and estimates of achieving desired key operating metrics and drivers; future weighted average cost of capital; and annual earnings multiples. Significant factors impacting these assumptions include estimates of future market share, key operating metrics such as churn and ARPU, level of competition, technological developments, interest rates, market economic trends, debt levels and the cost of debt. Note 14(c) of the Consolidated financial statements discusses sensitivity testing.

Investments

The recoverability of long-term investments

• The Company assesses the recoverability of its long-term investments on a regular, recurring basis. The recoverability of investments is assessed on a specific identification basis taking into consideration expectations about future performance of the investments and comparison of historical results to past expectations.
• The most significant assumptions underlying the recoverability of long-term investments are the achievement of future cash flow and operating expectations. The estimate of the Company's recoverability of long-term investments could change from period to period due to the recurring nature of the recoverability assessment and due to the nature of long-term investments (the Company does not control the investees).
• If the allowance for recoverability of long-term investments were inadequate, the Company could experience an increased charge to Other expense in the future. Such a provision for recoverability of long-term investments does not result in a cash outflow.

Future income tax liabilities

The composition of future income tax liabilities

• Future income liabilities are comprised of the tax effect of temporary differences between the carrying amount and tax basis of assets and liabilities as well as the tax effect of undeducted tax losses. The timing of the reversal of the temporary differences is estimated and the tax rate substantively enacted for the periods of reversal is applied to the temporary differences. The carrying amounts of assets and liabilities are based upon the amounts recorded in the financial statements and are therefore subject to accounting estimates that are inherent in those balances. The tax basis of assets and liabilities as well as the amount of undeducted tax losses are based upon the applicable income tax legislation, regulations and interpretations, all of which in turn are subject to interpretation. The timing of the reversal of the temporary differences and the timing of deduction of tax losses are estimated based upon assumptions of expectations of future results of operations.
• Assumptions underlying the composition of future income tax liabilities include expectations about future results of operations, the timing of reversal of deductible temporary differences and taxable temporary differences, and the timing of deduction of tax losses. These assumptions also affect classification between income and other taxes receivable or payable and future income tax liabilities. See Section 10.7 Tax matters. The composition of future income tax liabilities is reasonably likely to change from period to period because of changes in the estimation of these significant uncertainties.
• This accounting estimate is in respect of material asset and liability line items on the Company's Consolidated balance sheet comprising approximately 7% of total liabilities and shareholders' equity as at December 31, 2006. If the future were to adversely differ from management's best estimate of future results of operations and the timing of reversal of deductible temporary differences and taxable temporary differences, the Company could experience material future income tax adjustments. Such future income tax adjustments could result in acceleration of cash outflows at an earlier time than might otherwise be expected.

Advance billings and customer deposits

The accruals for CRTC deferral account liabilities

• The deferral account arose from the CRTC requiring the Company to defer the income statement recognition of a portion of the monies received in respect of residential basic services provided to non-high cost serving areas; such deferral requirement ended on May 31, 2006. The revenue deferral was based on the rate of inflation, less a productivity offset of 3.5%, and an "exogenous factor" that was associated with allowed recoveries in previous price cap regimes that have now expired. The critical estimate arises from the Company's recognition of the deferred amounts. The Company may recognize the deferred amounts upon the undertaking of qualifying actions, such as Service Improvement Programs in qualifying non-high cost serving areas, rate reductions (including those already mandated by the CRTC in respect of discounts on Competitor Digital Network services) and/or rebates to customers. As described in Note 19(a) of the Consolidated financial statements and Section 10.3 Regulatory — Price cap regulation, amounts in the deferral account are currently the subject of appeals to the Federal Court of Appeal by certain consumer groups and Bell Canada.
• Assumptions underlying the accruals for the CRTC deferral account that were uncertain at the time of making the estimate include what actions will ultimately qualify for recognition of deferred amounts and over what period of time qualifying deferred amounts are to be recognized in the Company's Consolidated income statement. The manner in which deferred amounts are recognized, and the amounts thereof, are reasonably likely to change as such recognition is ultimately dependent upon future decisions made by the CRTC, and resolution of appeals to the courts.
• This accounting estimate is in respect of an item within the advance billings and customer deposits line item on TELUS' Consolidated balance sheet and which, itself, comprises approximately 4% of total liabilities and shareholders' equity. If the Company's estimate of deferred amounts recognized, and the timing of the recognition thereof, were to differ materially from what the CRTC ultimately decides is allowable, revenues could possibly be materially impacted. Such a revenue impact would not be expected to be accompanied by a corresponding impact in net cash inflows. Should the consumer groups be successful in their appeal of the use of deferral account amounts, the Company may be required to remit a one-time refund to its entire local residential subscriber base. As the deferral account balance was fully provided for in previous financial statements, the potential refund will not impact TELUS' subsequent income from operations. Such a refund would result in a net cash outflow, potentially offset by reduced capital investment as the Company re-addresses its intent to extend broadband services to uneconomic remote and rural communities. In the event that Bell Canada is successful in its appeal, TELUS may realize additional revenue equal to the amount of the deferral account that would otherwise have been rebated by the CRTC. Such a revenue impact would not be expected to be accompanied by a corresponding impact in net cash inflows.

Employee defined benefit pension plans

Certain actuarial and economic assumptions used in determining defined benefit pension costs, accrued pension benefit obligations and pension plan assets

• The Company reviews industry practices, trends, economic conditions and data provided by actuaries when developing assumptions used in the determination of defined benefit pension costs and accrued pension benefit obligations. Pension plan assets are generally valued using market prices, however, some assets are valued using market estimates when market prices are not readily available. Defined benefit pension costs are also affected by the quantitative methods used to determine estimated returns on pension plan assets. Actuarial support is obtained for interpolations of experience gains and losses that affect the defined benefit pension costs and accrued benefit obligations. The discount rate, which is used to determine the accrued benefit obligation, is usually based upon the yield on long-term, highquality fixed term investments, and is set annually. The expected long-term rate of return is based upon forecasted returns of the major asset categories and weighted by plans' target asset allocations. Future increases in compensation are based upon the current benefits policies and economic forecasts.
• Assumptions used in determining defined benefit pension costs, accrued pension benefit obligations and pension plan assets include: discount rates, long-term rates of return for plan assets, market estimates and rates of future compensation increases. Material changes in overall financial performance and financial statement line items would arise from reasonably likely changes, because of revised assumptions to reflect updated historical information and updated economic conditions, in the material assumptions underlying this estimate. See Note 12(i) of the Consolidated financial statements for further analysis.
• This accounting estimate is in respect of a component of the largest operating expense line item on the Company's Consolidated income statement. If the future were to adversely differ from management's best estimate of assumptions used in determining defined benefit pension costs, accrued benefit obligations and pension plan assets, the Company could experience future increased defined benefit pension expense. The magnitude of the immediate impact is lessened, as the excess of net actuarial gains and losses in excess of 10% of the greater of the benefit obligation and the fair value of the plan assets is amortized over the average remaining service period of active employees of the plan.

8.2 Accounting policy developments

(Note 2 of the Consolidated financial statements)

Commencing with the Company's 2006 fiscal year, the Company adopted the amended recommendations of the Canadian Institute of Chartered Accountants (CICA) for measurement of non-monetary transactions (CICA Handbook Section 3830). The Company's operations were not materially affected by the amended recommendations.

Convergence with International Reporting Standards

In 2006, Canada's Accounting Standards Board ratified a strategic plan that will result in Canadian GAAP, as used by public companies, being converged with International Financial Reporting Standards over a transitional period currently expected to be about five years. The precise timing of convergence will depend on an Accounting Standards Board progress review to be undertaken by early 2008. As this convergence initiative is very much in its infancy as of the date of these Consolidated financial statements, it would be premature to currently assess the impact of the initiative, if any, on TELUS.

Comprehensive income

Commencing with the Company's 2007 fiscal year, the new recommendations of the CICA for accounting for comprehensive income (CICA Handbook Section 1530), for the recognition and measurement of financial instruments (CICA Handbook Section 3855) and for hedges (CICA Handbook Section 3865) will apply to the Company. In the Company's specific instance, the transitional rules for these sections require prospective implementation at the beginning of a fiscal year (the exception being in respect of the cumulative foreign currency translation adjustment, which is retroactively adjusted for at the beginning of the fiscal year of adoption). Currently, the concept of comprehensive income for purposes of Canadian GAAP, in the Company's specific instance, will be primarily to include changes in shareholders' equity arising from unrealized changes in the fair values of financial instruments.

Comprehensive income as prescribed by U.S. GAAP is largely aligned with comprehensive income as prescribed by Canadian GAAP, including the impacts of the new recommendations for the recognition and measurement of financial instruments and for hedges. In the Company's specific instance, however, there is currently a difference in other comprehensive income in that U.S. GAAP includes, in respect of pension and other defined benefit plans, the difference between the net funded plan status and the net accrued benefit asset or liability. Canadian GAAP does not include this currently, but an exposure draft from Canada's Accounting Standards Board is expected in the first half of 2007 that would eliminate this difference.

The majority of the impact on the Company of adopting the other comprehensive income and related standards currently arises from the Company's cross currency interest rate swap agreements, and to a lesser extent, the cash-settled equity forward agreements that the Company entered into in respect of share-based compensation.

Accounting changes and Business combinations

Commencing with the Company's 2007 fiscal year, the new recommendations of the CICA for accounting changes (CICA Handbook Section 1506) will apply to the Company. Most significantly, the new recommendations stipulate that voluntary changes in accounting policy are made only if they result in the financial statements providing reliable and more relevant information and that new disclosures are required in respect of changes in accounting policies, changes in accounting estimates and correction of errors. The Company is not currently materially affected by the new recommendations.

Capital disclosures

Effective December 31, 2006, the Company early adopted the new recommendations of the CICA for disclosure of the Company's objectives, policies and processes for managing capital (CICA Handbook Section 1535), as discussed further in Note 3 of the Consolidated financial statements.

Earnings per share

Amendments were proposed to the recommendations of the CICA for the calculation and disclosure of earnings per share (CICA Handbook Section 3500) and would have applied to the Company; such amendments had progressed to the typescript stage. In July 2006, the typescript with the proposed amendments was withdrawn and an announcement was made indicating that an International Financial Reporting Standards-based exposure draft from Canada's Accounting Standards Board would be issued at a later date, now expected in the first half of 2007.

Other recently issued accounting standards not yet implemented

Under U.S. GAAP, effective for its 2007 fiscal year, the Company is expected to be required to comply with accounting for uncertain income tax positions, as prescribed by Financial Accounting Standards Board Financial Interpretation No. 48, Accounting for Uncertainty in Income Taxes. TELUS has assessed the cumulative impact of adopting this new standard as of January 1, 2007. Based upon this review, the Company does not expect the adoption of this Interpretation will have a material impact on its Consolidated financial statements.