Here’s a short answer for you.
You file one tax return for the entire year that reports your business income along with any other personal income such as prizes or regular wages or investment income, plus your personal deductions, dependents, and credits. If you are self-employed, your tax return will include a form called schedule C which reports your business income and deducts your business expenses. The net profit from the business is your taxable business income, and that flows to the rest of form 1040 where it is combined with your other income and deduction information.
however, you may be required to pay estimated taxes four times a year based on your estimated business income. The tax system is supposed to be pay as you go. This is usually accomplished by wage withholding. When you are self-employed, you generally have to make an estimated tax payment four times a year based on your income earned during that quarter. If you pay too little in estimated taxes, you will owe more tax at the end of the year when you file your official form 1040. If you pay extra estimated taxes, you will get that back as a refund when you file your tax return.
The quarters are:
Estimated payment due April 15 for income earned between January and March.
Estimated payment due June 15 for income earned in April and May.
Estimated payment due September 15 for income earned June, July and August.
Estimated payment due January 15 for income earned between September and December.
The quarters are not uniform three months each as you will see, that was not a mistake on my part.
Once you determine the correct amount to pay in estimated taxes, the best way to pay electronically is at the IRS website, www.irs.gov/payments. If you pay online, the payment is linked to your Social Security number and you don’t need to send in any paper forms.
don’t forget that you may also owe state income tax payments on a quarterly basis.
TurboTax is only designed to prepare your final tax return at the end of the year and does not have a function to recommend an estimated payment based on your ongoing business activities. That function is contained in business software such as QuickBooks or Mint, or you may track your income and expenses on paper or using other software.
The longer answer above contains many links to further information on how to keep proper records and how to calculate your estimated taxes.
