Time period for assessments

In general, any assessment of tax, penalties, and interest must be made within one year after the expiration of the time allowed for assessing a deficiency in federal income tax. The period allowed for the assessment of federal income tax is generally three years from the time of filing of the taxpayer’s original return. Consequently, the period allowed for assessment of Colorado income tax is generally four years from the filing of the taxpayer’s original return. If the original return was filed prior to the due date, not including any extensions, the original return is considered to be filed on the due date.

In the case of the filing of a false or fraudulent return with intent to evade tax, the tax due may be assessed and collected at any time.