701—67.2 (452A) Statute of limitations, supplemental assessments and refund adjustments. After a return is filed, the department must examine it, determine fuel taxes due, and give notice of assessment to the taxpayer. If no return is filed, the department may determine the tax due and give notice thereof. See rule 701—67.5(452A). The period for the examination and determination of the correct amount of tax is unlimited in the case of a false or fraudulent return made with the intent to evade tax or in the case of a failure to file a return.
The department may, at any time within the period prescribed for assessment or refund adjustment, make a supplemental assessment or refund adjustment whenever it is ascertained that any assessment or refund adjustment is imperfect or incomplete in any respect.
If the assessment or refund adjustment is appealed (protested under rule 701—7.41(17A)) and is resolved whether by informal proceedings or by adjudication, the department and the taxpayer are precluded from making a supplemental assessment or refund adjustment concerning the same issue involved in such appeal for the same tax period unless there is a showing of mathematical or clerical error or a showing of fraud or misrepresentation.
The three-year period of limitation may be extended by a taxpayer by signing a waiver agreement form to be provided by the department. The agreement must stipulate the period of extension and must also provide that a claim for refund may be filed by the taxpayer at any time during the period of extension.
This rule is intended to implement Iowa Code section 452A.67 as amended by 1999 Iowa Acts, Senate File 136.