Important Due Dates for Businesses

January Description
15 Payroll taxes due for December payroll (monthly depositors 1)
25 Washington State B&O tax due for December revenue (monthly filers 2)
31 Washington State B&O tax due for previous quarter revenue (quarterly filers)
31 Washington State B&O tax due for previous year revenue (annual filers)
31 Final day to mail reporting form to recipients (W-2, 1099, etc.)
31 Fourth quarter payroll tax reporting forms due
31 Reporting forms (W-2, 1099, etc) due to IRS and Social Security Administration
February Description
15 Payroll taxes due for January payroll (monthly depositors)
25 Washington State B&O tax due for January revenue (monthly filers)
March Description
15 Partnership and S corporation income tax return filing deadline. Extension available to September 15. (Form 7004)
15 Payroll taxes due for February payroll (monthly depositors)
25 Washington State B&O tax due for February revenue (monthly filers)
April Description
15 Corporation income tax return filing deadline for calendar year corporations. Extension available to October 15 (Form 7004)3
15 First quarter corporate estimated income tax due for current year4
15 Payroll taxes due for March payroll (monthly depositors)
25 Washington State B&O tax due for March revenue (monthly filers)
30 Washington State B&O tax due for first quarter revenue (quarterly filers)
30 First quarter payroll tax reporting forms due
30 Personal property tax affidavits due to county tax assessors' office
30 First half property taxes due to county
May Description
15 Payroll taxes due for April payroll (monthly depositors)
25 Washington State B&O tax due for April revenue (monthly filers)
June Description
15 Second quarter corporate estimated income tax due for current year
15 Payroll taxes due for May payroll (monthly depositors)
25 Washington State B&O tax due for May revenue (monthly filers)
July Description
15 Payroll taxes due for June payroll (monthly depositors)
25 Washington State B&O tax due for June revenue (monthly filers)
31 Washington State B&O tax due for second quarter revenue (quarterly filers)
31 Second quarter payroll tax reporting forms due
August Description
15 Payroll taxes due for July payroll (monthly depositors)
25 Washington State B&O tax due for July revenue (monthly filers)
September Description
15 Final due date for S corporation and partnership income tax returns. No further extensions available.
15 Third quarter corporate estimated income tax due for current year
15 Payroll taxes due for August payroll (monthly depositors)
25 Washington State B&O tax due for August revenue (monthly filers)
October Description
15 Final due date for calendar year corporation income tax returns
15 Payroll taxes due for September payroll (monthly depositors)
25 Washington State B&O tax due for September revenue (monthly filers)
31 Washington State B&O tax due for third quarter revenue (quarterly filers)
31 Third quarter payroll tax reporting forms due
31 Second half property taxes due to county
November Description
15 Payroll taxes due for October payroll (monthly depositors)
25 Washington State B&O tax due for October revenue (monthly filers)
December Description
15 Fourth quarter corporate estimated income tax due for current year
15 Payroll taxes due for November payroll (monthly depositors)
25 Washington State B&O tax due for November revenue (monthly filers)

(1) This applies only to monthly depositors. If you have been notified by the IRS that you are a semi-weekly depositor, you must follow their schedule for depositing your payroll taxes.

(2) The State of Washington will notify you of your filing status: annual, quarterly or monthly.

(3) If you are a fiscal year corporation, other than June 30, your tax return is due by the 15th day of the fourth month following your year-end. For June 30, due date is 15th day of third month.

(4) The due dates listed for corporate estimated income tax apply to calendar year corporations. If you are a fiscal year corporation, the payments are due by the 15th day of the 4th, 6th, 9th and 12th month of your fiscal year.