September
15
- Monthly-filers
Form 941 federal tax deposit due
- DC sales
tax return and payment due, monthly filers
- Form 1040-ES
voucher #3 with payment due
- DC, Virginia
and Maryland individual estimated tax payment #3 due
- Maryland
income tax withheld return and payment due, monthly filers
- Extended Returns Forms
1120S, 1065 and 1041
20
- Virginia
income tax withheld return and payment due, monthly filers
- DC income
tax withheld payment return and payment due, monthly filers
- Virginia
and Maryland sales tax return and payment due, monthly filers