National Internal Revenue Code (NIRC)
Section 267. Declaration under Penalties of Perjury. - Any declaration, return and other statement required under this Code, shall, in lieu of an oath, contain a written statement that they are made under the penalties of perjury. Any person who willfully files a declaration, return or statement containing information which is not true and correct as to every material matter shall, upon conviction, be subject to the penalties prescribed for perjury under the Revised Penal Code.