The IRS has rules that you may be REQUIRED to make these payments (one per quarter – 1st due April 15th, then July 15th, Oct 15th, and January 15th. With you owing $3,000 this year (for 2015), that may kick you into having to make estimated payments (one of the rules is how much you owe the previous year). If per the rules, you are supposed to make estimated tax payments, but don’t you can be assessed penalties even if you pay your tax due by April 15th! If you have an accountant / tax person, you may want to ask them – if you don’t you may want to find one. Our accountant has been very helpful with tax planning etc. We really only use them for taxes and to meet once or twice a year to verify that our estimated payment are on track with business income – they don’t do our day to day accounting or anything.