If I anticipate a sizable capital gain on the sale of an investment during the year, do I need to make a quarterly estimated tax payment during the tax year?
You can make your first estimated payment by the due date for the period in which the income is received. You can either pay your entire estimated tax by the due date for that period or you can pay it in installments by the due date for that period and the due dates for the remaining periods.
If you are making estimated tax payments you can increase your quarterly estimated tax payments or increase your Federal income tax withholding to cover the tax liability. If you have the proper amount withheld you may not be required to make estimated tax payments nor have to file Form 2210 (PDF), Underpayment of Estimated Tax by Individuals, Estates and Trusts, with your tax return (as you would if you just increased the remaining estimated tax payments). If you wait and make increased estimated tax payments in the later quarters, you would have to file Form 2210 with your tax return because we do not know when you received the income. Since you really did not receive the income evenly throughout the year, you have to tell us when the income was received by filing Form 2210.