To be considered unmarried on the last day of the tax year, a married person must meet which conditions:

Answer and Explanation: The question refers to "married filing jointly" which is an income tax filing status available to any couple that has wed as of Dec. 31 of the tax year which is also the last day of the year. This type of filing offers numerous advantages, however, to be   considered unmarried on the last day of the tax year, a married person must meet which conditions which include:

1. The couple having apart for the last six months of the tax year. This does not include temporary absences (business, school, military service, healthcare).

2. A condition where tax returns are filed separately.

3. Half the cost of keeping up your home during the tax year is paid by each spouse.

4. The main home of your child, stepchild, or foster child belongs to you for more than half of the tax year.

In any case, the married filing jointly is advantageous to couples that have a spouse who earns significantly more money than the other, allowing them to use only one tax return, even though both spouses are equally responsible for the return and any taxes and penalties owed.