Our software can be found at turbotax.intuit.com.
The underpayment penalty interview questions are located in the Other Tax Situations section.
The best way to comply is to calculate your profit each month and then go online to IRS.gov/payments and make an estimated payment (I suggest 15.3% of the profit at least to cover the self-employment tax.).
MAKE SURE the estimated payment is being applied to the tax year that you are earning the income in; review closely your entries on the IRS website.
You do not get penalized for not making quarterly payments; the penalty applies if you underpay your tax owed during the course of the year. So if you lose money the first half of the year in your self-employed business, you do not have an estimated tax obligation for that perio.
