The Electronic Federal Tax Payment System (EFTPS) is a free tax payment system designed with all taxpayers in mind. This can be used instead of the Electronic Funds Withdrawal if you would prefer to set up your payment(s) separately from filing your return.
Using the EFTPS system is an easy way to pay your federal taxes for individuals as well as businesses. Make ALL of your federal tax payments including federal tax deposits (FTDs), installment agreements, and estimated tax payments using Electronic Federal Tax Payment System.
To make estimated tax payments online, you will need to establish an account at EFTPS Online
Once you have an account established at that site, you can schedule automatic withdrawals for your quarterly estimated taxes, specifying the amounts and the dates of the payments.
The EFTPS payment information does not get transmitted when you e-file. You would need to indicate that you are paying by check and then arrange payment through EFTPS.
For estimated tax purposes, the year is divided into four payment periods. Each period has a specific payment due date. If you do not pay enough tax by the due date of each of the payment periods, you may be charged a penalty even if you are due a refund when you file your income tax return.
Your first estimated tax payment is usually due the 15th of April. You may pay the entire year's estimated tax at that time, or you may pay your estimated tax in four payments. Generally, the four payments are due April 15th, June 15th, September 15, and January 15th of the following year.
If the due date for making an estimated tax payment falls on a Saturday, Sunday, or legal holiday, the payment will be on time if you make it on the next day that is not a Saturday, Sunday, or legal holiday.
For additional information please refer to IRS Publication 505