IRS False Returns
§ 7206.  Fraud and false statements

Any person who —

(1) Declaration under penalties of perjury

Willfully makes and subscribes any return, statement, or other document, which contains or is verified by a written declaration that it is made under the penalties of perjury, and which he does not believe to be true and correct as to every material matter.

This statute is not violated unless the taxpayer has made, signed and filed a false tax return or other document.  The elements of this offense are: (1) making and subscribing a false return or other document; (2) which states by written declaration that it was signed under penalties of perjury; (3) the falsity in the return or document was material; and (4) willfulness.