If you are self-employed you may be require to make Estimated Tax Payments. These payments are do on the following dates for 2014:
April 15, 2014
June 16, 2014
September 15, 2014, and
January 15, 2015.
Estimated Tax Payments are critical to ensuring you will not owe taxes when you file your 2014 tax return. You may also owe an Estimated Tax Payment penalty if you do not make sufficient Estimated Tax Payments.
If you are unsure of the amount or dates required with making your payments you should review the IRS website for a tool to assist you in calculating your tax liability or see your tax adviser.