September 2024 Business Due Dates

September 16 - S Corporations

File a 2023 calendar year income tax return (Form 1120-S) and pay any tax due. This due date applies only if you requested an automatic 6-month extension. Provide each shareholder with a copy of their Schedule K-1 (Form 1120-S) or a substitute Schedule K-1 and, if applicable, Schedule K-3 (Form 1120-S) or substitute Schedule K-3 (Form 1120-S).

September 16 - Corporations 

Deposit the third installment of estimated income tax for 2023 calendar year

September 16 -  Social Security, Medicare and withheld income tax

If the monthly deposit rule applies, deposit the tax for payments in August.

September 16 - Nonpayroll Withholding

If the monthly deposit rule applies, deposit the tax for payments in August.

September 16 - Partnerships

File a 2023 calendar year return (Form 1065). This due date applies only if you were given an additional 5-month extension. Provide each partner with a copy of K-1 (Form 1065) or a substitute Schedule K-1.

September 30 - Fiduciaries of Estates and Trusts

File a 2023 calendar year return (Form 1041). This due date applies only if you were given an extension of 5 1/2 months. If applicable, provide each beneficiary with a copy of K-1 (Form 1041) or a substitute Schedule K-1.

Weekends & Holidays:

If a due date falls on a Saturday, Sunday or legal holiday, the due date is automatically extended until the next business day that is not itself a legal holiday. 

Disaster Area Extensions:

Please note that when a geographical area is designated as a disaster area, due dates will be extended. For more information whether an area has been designated a disaster area and the filing extension dates visit the following websites:

FEMA: https://www.fema.gov/disaster/declarations
IRS: https://www.irs.gov/newsroom/tax-relief-in-disaster-situations

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