The depreciation allowance includes an allowance for normal obsolescence which should be taken into account to the extent that the expected useful life of property will be shortened by reason thereof. Obsolescence may render an asset economically useless to the taxpayer regardless of its physical condition. Obsolescence is attributable to many causes, including technological improvements and reasonably foreseeable economic changes. Among these causes are normal progress of the arts and sciences, supersession or inadequacy brought about by developments in the industry, products, methods, markets, sources of supply, and other like changes, and legislative or regulatory action. In any case in which the taxpayer shows that the estimated useful life previously used should be shortened by reason of obsolescence greater than had been assumed in computing such estimated useful life, a change to a new and shorter estimated useful life computed in accordance with such showing will be permitted. No such change will be permitted merely because in the unsupported opinion of the taxpayer the property may become obsolete. For rules governing the allowance of a loss when the usefulness of depreciable property is suddenly terminated, see § 1.167(a)-8. If the estimated useful life and the depreciation rates have been the subject of a previous agreement, see section 167(d) and § 1.167(d)-1.
The preliminary Code is a preliminary release of the Internal Revenue Code of 1986 (the "Code") by the Office of the Law Revision Counsel and is subject to further revision before it is released again as a final version. The source of the preliminary Code used in TouchTax is available here: https://uscode.house.gov/download/download.shtml. The Code is a consolidation and codification by subject matter of the general and permanent laws of the U.S. prepared by the Office of the Law Revision Counsel of the U.S. House of Representatives. The Treasury Regulations are a codification of the general and permanent rules published in the Federal Register by the departments and agencies of the federal government. The version of the Treasury Regulations available within TouchTax is part of the Electronic Code of Federal Regulations which is not an official legal edition of the Code of Federal Regulations but is an editorial compilation of CFR material and Federal Register amendments produced by the National Archives and Records Administration's Office of the Federal Register (OFR) and the Government Publishing Office. The source of the CFR used in TouchTax is available here: https://www.govinfo.gov/bulkdata/ECFR/title-26. Those using TouchTax for legal research should verify their results against the printed versions of the Code and Treasury Regulations. TouchTax is copyright 2024 by Com-Lab (Mobile). Learn more at http://touchtax.edrich.de.