If the parents were married but filed separate returns, enter the name and SSN of the parent who had the higher taxable income. If you do not know which parent had the higher taxable income, see Pub. If the custodial parent remarried and filed a joint return with his or her new spouse, enter the name and SSN of the person listed first on the joint return, even if that person is not the child's parent. If the custodial parent and his or her new spouse filed separate returns, enter the name and SSN of the person with the higher taxable income, even if that person is not the child's parent. If the child had earned income, use the worksheet on page 2 to figure the amount to enter on line 1.
Earned income includes wages, tips, and other payments received for personal services performed.
If the parent filed a joint return, enter the taxable income shown on that return even if the parent's spouse is not the child's parent. Skip lines 7 through 16. Complete line 17 and enter that amount on line 18. Also enter No Effect on the dotted line next to line 18. Line 9 Figure the tax using the Tax Table, Tax Rate Schedules, the Capital Gain Tax Worksheet, or Schedule D or J, whichever applies.