October 15th
Last day to file your income tax returns. You must have received from the IRS an approval form that was cut of of form 2688. This must be attached to your filed return.

September 15th
3rd Quarter estimated tax coupons & payments due.

January 15th
4th Quarter estimated tax coupons and payments due.

15th of each month
All monthly payroll depositors must deposit payroll taxes for the previous months payroll.