Segment information SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES continued v. Treasury stock

PERUSAHAAN PERSEROAN PERSERO PT TELEKOMUNIKASI INDONESIA Tbk AND SUBSIDIARIES NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS As of June 30, 2017 and For the Six Months Period Then Ended unaudited Figures in tables are expressed in billions of Rupiah, unless otherwise stated 33 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES continued ab. Critical Accounting Estimates and Judgements continued i. Retirement benefits continued If there is an improvement in the ratings of such Government bonds or a decrease in interest rates as a result of improving economic conditions, there could be a material impact on the discount rate used in determining the post-employment benefit obligations. Other key assumptions for retirement benefit obligations are based in part on current market conditions. Additional information is disclosed in Notes 29 and 30. ii. Useful lives of property and equipment The Group estimates the useful lives of its property and equipment based on expected asset utilization, considering strategic business plans, expected future technological developments and market behavior. The estimates of useful lives of property and equipment are based on the Group’s collective assessment of industry practice, internal technical evaluation and experience with similar assets. The Group reviews its estimates of useful lives at least each financial year-end and such estimates are updated if expectations differ from previous estimates due to changes in expectation of physical wear and tear, technical or commercial obsolescence and legal or other limitations on the continuing use of the assets. The amounts of recorded expenses for any year will be affected by changes in these factors and circumstances. A change in the estimated useful lives of the property and equipment is a change in accounting estimates and is applied prospectively in profit or loss in the period of the change and future periods. Details of the nature and carrying amounts of property and equipment are disclosed in Note 9. iii. Provision for impairment of receivables