26 CFR § 1.167(a)-3 - Intangibles.
(a) In general. If an intangible asset is known from experience or other factors to be of use in the business or in the production of income for only a limited period, the length of which can be estimated with reasonable accuracy, such an intangible asset may be the subject of a depreciation allowance. Examples are patents and copyrights. An intangible asset, the useful life of which is not limited, is not subject to the allowance for depreciation. No allowance will be permitted merely because, in the unsupported opinion of the taxpayer, the intangible asset has a limited useful life. No deduction for depreciation is allowable with respect to goodwill. For rules with respect to organizational expenditures, see section 248 and the regulations thereunder. For rules with respect to trademark and trade name expenditures, see section 177 and the regulations thereunder. See sections 197 and 167(f) and, to the extent applicable, §§ 1.197-2 and 1.167(a)-14 for amortization of goodwill and certain other intangibles acquired after August 10, 1993, or after July 25, 1991, if a valid retroactive election under § 1.197-1T has been made.
(b) Safe harbor amortization for certain intangible assets -
(1) Useful life. Solely for purposes of determining the depreciation allowance referred to in paragraph (a) of this section, a taxpayer may treat an intangible asset as having a useful life equal to 15 years unless -
(i) An amortization period or useful life for the intangible asset is specifically prescribed or prohibited by the Internal Revenue Code, the regulations thereunder (other than by this paragraph (b)), or other published guidance in the Internal Revenue Bulletin (see § 601.601(d)(2) of this chapter);
(iii) The intangible asset has a useful life the length of which can be estimated with reasonable accuracy; or
(iv) The intangible asset is described in § 1.263(a)-4(d)(8) (relating to certain benefits arising from the provision, production, or improvement of real property), in which case the taxpayer may treat the intangible asset as having a useful life equal to 25 years solely for purposes of determining the depreciation allowance referred to in paragraph (a) of this section.
(2) Applicability to acquisitions of a trade or business, changes in the capital structure of a business entity, and certain other transactions. The safe harbor useful life provided by paragraph (b)(1) of this section does not apply to an amount required to be capitalized by § 1.263(a)-5 (relating to amounts paid to facilitate an acquisition of a trade or business, a change in the capital structure of a business entity, and certain other transactions).
(3) Depreciation method. A taxpayer that determines its depreciation allowance for an intangible asset using the 15-year useful life prescribed by paragraph (b)(1) of this section (or the 25-year useful life in the case of an intangible asset described in § 1.263(a)-4(d)(8)) must determine the allowance by amortizing the basis of the intangible asset (as determined under section 167(c) and without regard to salvage value) ratably over the useful life beginning on the first day of the month in which the intangible asset is placed in service by the taxpayer. The intangible asset is not eligible for amortization in the month of disposition.