September 2018 Business Due Dates

September 17 - S Corporations

File a 2017 calendar year income tax return (Form 1120S) 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 K-1 (Form 1120S) or a substitute Schedule K-1.

September 17 - Corporations 

Deposit the third installment of estimated income tax for 2018 for calendar year

September 17 -  Social Security, Medicare and withheld income tax

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

September 17 - Nonpayroll Withholding



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

September 17 - Partnerships

File a 2017 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 17 - Electing Large Partnerships 

File a 2017 calendar year return (Form 1065-B). This due date applies only if you were given a 6-month extension. March 15 was the due date for furnishing Schedules K-1 or substitute Schedule K-1 to the partners.



Share this article...

Want our best tax and accounting tips and insights delivered to your inbox?

Sign up for our newsletter.

I confirm this is a service inquiry and not an advertising message or solicitation. By clicking “Submit”, I acknowledge and agree to the creation of an account and to the and .

Privileged And Confidential
This communication and any accompanying documents are confidential and privileged. They are intended for the sole use of the addressee. If you receive this transmission in error, you are advised that any disclosure, copying, distribution, or the taking of any action in reliance upon this communication is strictly prohibited. Moreover, any such disclosure shall not compromise or waive the attorney-client, accountant-client, or other privileges as to this communication or otherwise. If you have received this communication in error, please contact me at the above email address. Thank you.

Disclaimer
Any accounting, business or tax advice contained in this communication, including attachments and enclosures, is not intended as a thorough, in-depth analysis of specific issues, nor a substitute for a formal opinion, nor is it sufficient to avoid tax-related penalties. If desired, Tobi Li Marshall CPA, APC would be pleased to perform the requisite research and provide you with a detailed written analysis. Such an engagement may be the subject of a separate engagement letter that would define the scope and limits of the desired consultation services.