SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES continued v. Treasury stock

PERUSAHAAN PERSEROAN PERSERO PT TELEKOMUNIKASI INDONESIA Tbk AND ITS SUBSIDIARIES NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS As of December 31, 2015 and for the Year Then Ended Figures in tables are expressed in billions of Rupiah, unless otherwise stated 42 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES continued ac. Critical accounting estimates and judgements continued

i. Retirement benefits

The present value of the retirement benefit obligations depends on a number of factors that are determined on an actuarial basis using a number of assumptions. The assumptions used in determining the net cost income for pensions include the discount rate. Any changes in these assumptions will impact the carrying amount of retirement benefit obligations. The Group determines the appropriate discount rate at the end of each reporting period. This is the interest rate that should be used to determine the present value of estimated future cash outflows expected to be required to settle the obligations. In determining the appropriate discount rate, the Group considers the interest rates of Government bonds that are denominated in the currency in which the benefits will be paid and that have terms to maturity approximating the terms of the related retirement benefit obligations. 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 benefits obligations. Other key assumptions for retirement benefit obligations are based in part on current market conditions. Additional information is disclosed in Notes 33, 34 and 35. ii. Useful lives of property and equipment The Group estimate the useful lives of their 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 PERUSAHAAN PERSEROAN PERSERO PT TELEKOMUNIKASI INDONESIA Tbk AND ITS SUBSIDIARIES NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS As of December 31, 2015 and for the Year Then Ended Figures in tables are expressed in billions of Rupiah, unless otherwise stated 43

3. BUSINESS COMBINATIONS

Acquisition of Contact Centers Australia Pty. Ltd.