What is Estimated Tax?
Estimated tax is a method of paying tax on income that is not subject to withholding tax. This can include income from self-employment, business earnings, interest, rent, dividends and other sources. Self Employment Tax Uniondale.
The IRS requires estimated tax to be paid quarterly, typically in 4 equal installments. If you underpay your estimated tax, you will have to write a bigger check to the IRS when you file your tax return. If you overpay your estimated tax, you will receive the excess amount as a tax refund (similar to how withholding tax works).