1. (a) The change of election must be made by filing a complete amended New York State personal income tax return for each taxable year involved, properly signed by each taxpayer who made or agreed to the original election. If any other taxpayer was not required to file a New York State personal income tax return by reason of the original election, but is required to file a New York State personal income tax return by reason of the change of election, the amended New York State personal income tax return by the taxpayer who filed originally must be accompanied by a New York State personal income tax return signed by such other taxpayer.
2. (b) Where the change of election results in an underpayment of New York State personal income tax on the part of any taxpayer required to file a New York State personal income tax return or amended New York State personal income tax return pursuant to subdivision (a) of this section, any New York State personal income tax or additional New York State personal income tax resulting from the change of election will be deemed to have been assessed on the date of filing the original New York State personal income tax return, and the change will not be effective, unless all New York State personal income tax due from each such taxpayer plus any interest thereon as required by section 684 of the Tax Law, is or has been paid at the time of New York State personal income tax return or amended New York State personal income tax return making the change of election is filed. For the purposes of this subdivision, an overpayment by one spouse will be treated as payment of New York State personal income tax due from the other spouse, provided the spouse who made the overpayment authorizes such application thereof.
3. (c) Where the change of election results in an overpayment of New York State personal income tax, the New York State personal income tax return or amended New York State personal income tax return required by subdivision (a) of this section will be deemed a claim for refund for the purposes of section 687 of the Tax Law, but refund will be allowable only if such New York State personal income tax return or amended New York State personal income tax return is filed within the time prescribed by section 687 of the Tax Law, generally, three years from the filing of the New York State personal income tax return in which the original election was made, or two years from the payment of the New York State personal income tax, whichever is later. To the extent that a change of election serves or operates, as an offset, to reduce a deficiency of New York State personal income tax under section 681 of the Tax Law for the same taxable year, such change of election is not deemed to result in an overpayment and such offset will be allowed without regard to the time limitation mentioned above. Likewise, such time limitation will not apply to a change of election which, considered independently of any other adjustment for the taxable year, would have resulted in a deficiency or under-payment of New York State personal income tax for such taxable year.
4. (d) Where the proposed change of election involves a joint New York State personal income tax return of a husband and wife or separate New York State personal income tax returns of the spouses on one form (either as the original New York State personal income tax return or as an amended New York State personal income tax return) and the sum of the payments by both spouses on the original New York State personal income tax return or returns exceeds the New York State personal income taxes dues after giving effect to the change of election, refund of the excess may be made payable to both spouses.
5. (e) If more than one election is being changed for any taxable year, all such changes may be shown in one New York State personal income tax return or amended New York State personal income tax return for that year, filed by each taxpayer who made or agreed to each of the original elections.
6. (f) No change of election pursuant to this section will be effective if disapproved by the Tax Commission.

The following are the conditions under which a taxpayer may change his election with respect to any of the matters listed in section 161.3(a) of this Part: