(a) The amount of any tax imposed by the Code (other than a tax collected by means of stamps) shall be assessed within 3 years after the return was filed. For rules applicable in cases where the return is filed prior to the due date thereof, see section 6501(b). In the case of taxes payable by stamp, assessment shall be made at any time after the tax became due and before the expiration of 3 years after the date on which any part of the tax was paid. For exceptions and additional rules, see subsections (b) to (g) of section 6501, and for cross references to other provisions relating to limitations on assessment and collection, see sections 6501(h) and 6504.
(b) No proceeding in court without assessment for the collection of any tax shall be begun after the expiration of the applicable period for the assessment of such tax.
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 2022 by Com-Lab (Mobile). Learn more at http://touchtax.edrich.de.