Tax Due Dates.
June 2026
June 15 – Q2 estimated tax payment due (individuals & corporations)
June 15 – US citizens/residents living abroad: deadline to file 2025 federal income tax return (automatic 2-month extension)
July 2026
July 31 – Employer quarterly federal tax return (Form 941) for Q2
September 2026
September 15 – Q3 estimated tax payment due (individuals & corporations)
September 15 – Extended deadline for S-corps and partnerships (Forms 1120-S, 1065) that filed for a 6-month extension in March
October 2026
October 15 – Extended deadline for individual federal income tax returns (Form 1040) that received an extension in April
October 15 – Extended deadline for C-corps (Form 1120) with a calendar year end
October 31 – Employer quarterly federal tax return (Form 941) for Q3
December 2026
December 15 – Q4 estimated tax payment for corporations (calendar-year C-corps)
December 31 – Last day to make charitable contributions deductible for 2026; last day for required minimum distributions (RMDs); last day to maximize 401(k) elective deferrals for the year

