Corporations deposit the fourth installment of estimated tax for 2026.

Non-farm employers file Form 941 for the third quarter to report wages paid, and social security, Medicare, and income tax withheld from wages, and compute employer matching social security payments

Individuals file a 2025 income tax return (Form 1040) if an automatic extension was requested

Corporations file a 2025 calendar year tax return (Form 1120) if you requested an automatic extension

Third quarter estimate is due for 2026 for individuals that pay estimated taxes

S Corporations file a 2025 calendar year income tax return (Form 1120S) if you requested an automatic extension

Partnerships file a 2025 calendar year income tax return (Form 1065) if you requested an automatic extension

Corporations deposit third installment of estimated tax for 2026