What determines paying taxes quarterly?

[VolvoGirl · Accepted solution]

You don't have to pay quarterly but if you owe too big of a Tax Due on  your return you may owe an underpayment penalty.  I assume you are asking about quarterly estimated payments for your business income?  Or are you asking about paying employees and filing quarterly payroll taxes?

For SE self employment tax - if you have a net profit (after expenses) of $400 or more you will pay 15.3% SE Tax on 92.35% of your net profit in addition to your regular income tax on it. So if you have other income like W2 income your extra business income might put you into a higher tax bracket.

You must make quarterly estimated tax payments for the current tax year if both of the following apply:
- 1. You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits.
 
- 2. You expect your withholding and credits to be less than the smaller of:
    90% of the tax to be shown on your current year’s tax return, or
  100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months.)