It is asking for my parent's taxable income from Form 1040, but I am no longer being claimed as a dependent nor do I have this information. Can I leave it blank?

[DawnC]

Unfortunately, no.  Because of your age/student status and your unearned income, you fall into a category of special taxing.  The unearned income is taxed at different rates and is dependent upon your parent's income.  

The Kiddie Tax is the tax levied on the portion of your child's unearned income that exceeds $2,200. Children who only had earned income from a job or self-employment, don’t make enough money to be required to file, or are filing jointly with their spouses are exempt from the Kiddie Tax.

When does the Kiddie Tax kick in?

For the tax year 2019, the Kiddie Tax applies if your child has unearned income (usually from investments) exceeding $2,200, is required to file a return, isn’t filing jointly, and was age:

• 17 or younger at the end of 2019;
• 18 at the end of 2019, but only if their earned income (excluding scholarships in the case of a full-time student) didn’t exceed half of their support costs in 2019; or
• 19–23 at the end of 2019, but only if they were full-time students and their earned income (excluding scholarships) didn’t exceed half of their support costs in 2019.

If you leave it blank, you may get errors when attempting to e-file.  

[MrsO]

Filing my daughters tax return.  I put that she is claimed by someone else but it's ask for all my information and my 1040 income.  Once I entered this she now has to pay over $600.00 to the Federal governement.  Why is that?  She didn't make that money I did and I'm already paying the government.

[SamS1]

She must have unearned income greater than $2,200.  If a child’s unearned income is more than $2,200, Form 8615 is used to compute the child’s tax. File Form 8615 with the child’s return if:

• The child has more than $2,200 of unearned income,
• The child is required to file a tax return (if the parents qualify and elect to report the child’s income on their return, the child is not required to file a return or
• The child meets certain age requirements.  Under 18, Kiddie Tax Applies.  Age 18-23, KiddieTax applies unless child provides more than 1/2 support with earned income.
• At least one of the child’s parents was alive at the end of the tax year, and the child does not file a joint return.

If the filing requirements are met, Form 8615 is required even if the child is not a dependent.

You mentioned is is being claimed by someone else.  If she is married, it would be best to file a joint return with her spouse.