Allowable depreciation
(3) Allowable depreciation or amortization. The phrase deduction allowable for the taxable year for exhaustion, wear and tear, obsolescence, or amortization and references in this paragraph to allowable depreciation or amortization include deductions allowable for the taxable year under sections 162, 167, 212, or 611 for the depreciation or amortization of section 1250 property. Such phrase does not include depreciation allowable in the year in which the section 1250 property is disposed of. For the determination of allowable depreciation or amortization for taxable years in which the taxpayer has taken no deduction, see 1.1016-3(a)(2). (4) Straight line depreciation. (i) For purposes of computing the depreciation which would have been allowable for the taxable year if the taxpayer had depreciated the property under the straight line method for each taxable year of its useful life, the taxpayer must use the same useful life and salvage value as was used for the first taxable year in which the taxpayer depreciated or amortized the property (subject to redeterminations made pursuant to 1.167(a)-1 (b) and (c)). If, however, for any taxable year, no useful life was used under the method of depreciation or amortization used or an artificial period was used, such as, for example, by application of section 167(k), or salvage value was not taken into account in determining the annual allowances, such as, for example, under the declining balance method, then, for purposes of computing the depreciation which would have been allowable under the straight line method for the taxable year