August 2:
- Employers. File Form 941 for 2nd quarter 2010.
- Employers. Form 5500 or 5500-EZ for calendar year 2009 due if you maintain an employee benefit plan, or file Form 5558 to request an extension.
September 15:
- Individuals. 3rd installment of 2010 estimated tax due.
- Calendar-year C Corporations.3rd installment of 2010 estimated tax due.
- Corporations. 2009 returns due for calendar-year C and S corporations (Form 1120 &1120S) if on extension.
- Partnerships. Calendar year 2009 return due (Form 1065) if on extension.