Blog

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...

Never miss a story.

Sign up for our newsletters and get our articles delivered right to your inbox.

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 .
I consent to receive SMS messages

Palm Desert Office

73733 Fred Waring Dr Ste 105
Palm Desert, California 92260

Redding Office

2205 Hilltop Dr Suite 119
Redding, CA 96002
How Can We Help? Have a question?
Hello, the CGC bot can help answer your questions 24/7. For other questions not listed here use the Ask Me A Question form and one of our staff will respond within 48 hours.
Please fill out the form and our team will get back to you shortly The form was sent successfully