Estimated tax refers to the method used to pay taxes on income that is not subject to withholding. This includes earnings from self-employment, interest, dividends, rents, and alimony. Taxpayers who do not have taxes withheld from other taxable income should also make estimated tax payments.
Estimated tax payments can be made up until December 31 of the current year. Payments made by this deadline are credited toward the tax liability for that tax year. However, taxes cannot be paid as estimated payments after the tax year has ended.
Important: Please note that paying a tax liability (taxes owed) for a previous tax year does not count as an estimated tax payment.