You should file your quarterly estimated tax payments using Form 502D, Declaration of Estimated Tax (or your preprinted voucher Form 502DEP) with your payment by the following dates:
- First quarter - April 15, 2018
- Second quarter - June 15, 2018
- Third quarter - September 15, 2018
- Fourth quarter - January 15, 2019
If the due date falls on a Saturday, Sunday or legal holiday, then the return or voucher would be due on the next business day.
If you file your first three quarterly payments, you donít have to file and pay the fourth quarter estimated payment due on January 15 as long as you file your final individual return before January 31 and pay your full balance due with that return.