Another thing----you mentioned having several W-2 jobs. When you have a W-2 job the employer withholds as if that job is your only job. So with three employers relatively low amounts of income, you probably did not have enough tax withheld from your paychecks to meet your tax liability.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
