39-22-303.6–15 Election to Treat All Income as Apportionable Income. Basis and Purpose. The bases of this rule are §§ 39-21-112, 39-22-301, 39-22-303,

39-22-303.6, C.R.S. The purpose of this rule is to clarify how a taxpayer makes an election to treat all income as apportionable income. (1) Every year, taxpayers may elect to treat all income as apportionable income. (a) The election to treat all income as apportionable income must be made on or before the extended due date of the return (the fifteenth day of the tenth month following the close of the tax year) by marking the appropriate box on the original return. (b) Once the original return has been filed for the year, the election may not be changed even if the extended due date for the year has not passed. (c) Filing a return without making the election as provided in paragraph (1)(a) constitutes the non-exercise of the election for that tax year, even if the return is calculated with all income as apportionable income. (d) The failure to file a return prior to the extended due date of the return constitutes the non-exercise of the election for that tax year. (2) If the election described in this rule is made for the income tax year, all income of the taxpayer is apportionable income and is included in the denominator and, if appropriate, the numerator of the taxpayer’s receipts factor if not excluded pursuant to §§ 39-22-303.6(6)(d)(III) or (6)(f), C.R.S.