Tax Return Due Dates for 2017 Business Taxes

Including Due Dates for Extended Business Tax Returns

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2017 Tax Return Due Dates for Business Types 

Sole Proprietorship and Single-member LLC returns on Schedule C: April 17, 2018

Partnership returns  on Form 1065 with Schedule K-1s: March 15, 2018  

Multiple-member LLC returns on Form 1065 with Schedule K-1 is: March 15, 2018

S corporation returns on Form 1120 S: March 15, 2018

C corporation returns on Form 1120: for December 31 year-end corporations, the deadline is April 17, 2018. Corporations must file by the 15th day of the 4th month after the end of its tax year. But corporations with a fiscal year ending June 30 must file by the 15th day of the 3rd month after the end of its tax year. 

Extension Deadlines for 2017 Business Tax Returns

Deadlines for extended business tax returns

  • Schedule C for sole proprietors and single-member LLC's: extension until October 16, 2017 (no change) filed with personal tax return
  • Partnership and multiple-member LLC filing as partnership extension deadline is September 17, 2018 (no change)
  • S corporation extension deadline is September 17, 2018 (no change)
  • Corporation extension deadline is October 15, 2018 (automatic extension allowed)

Changes: New Tax Return Due Dates for Partnership and C Corporation Returns

Partnership Tax Returns: Beginning with 2016 tax returns and continuing in future years), partnership tax returns, filed on Form 1065, must be filed by the 15th day of the third month after the tax year end date. For most partnership returns, that's March 15. (The previous due date was April 15). The earlier deadline gives partners a chance to receive Schedule K-1's before the personal tax return due date. 

C Corporation Tax Returns: Effective with the 2016 tax year (filing in 2017), there are new deadlines for filing corporate tax returns on Form 1120, depending on the corporation's

  • If fiscal year-end is December 31, the new deadline for 2017 returns: April 17, 2018. 
  • Fiscal year-end other than December 31 is the 15th day of the 4th month after year end

How Tax Return Due Dates are Determined Each Year

If the tax return due date falls on a weekend or holiday, the due date is moved to the first following work day; for example, if April 15 is on Sunday, the due date is Monday, April 16.

For example, the for personal and partnership taxes is April 15. BUT, in 2018 April 15 is on a Sunday, and Monday, April 17, is a holiday in the District of Columbia, so the return is due on Tuesday, April 17. 

More Details on 2017 Business Tax Return Due Dates

Here is a list of the types of business entities and their tax return due dates for 2017 tax returns:

A business is an extension of the person running the business, so its year-end is December 31, and the tax return due date is the same as the individual's - April 17 in 2018. Sole proprietor businesses file their on, which is part of the group of forms and schedules that go along with the person's personal tax return.

The due date for 2017 is April 17, 2018, the same as your individual tax return date.

Single-member LLC

A (that is, an LLC with only one owner) is taxed like a sole proprietorship, using to calculate , so the tax returns are due and taxes are payable on , for the prior year. The due date for 2017 Schedule C forms, along with the owner's personal tax return, is April 17, 2018.


A return is filed as an on , and tax is owed on the individual partner tax return. Form 1065 is now due on 15th day of the 3rd month after the end of the partnership's tax year.

For a December 31 year-end, the due date is March 15. For 2017 tax return filing, the partnership return due date is March 15, 2018. March 15 is also the due date for Individual partners to receive  showing their individual share of the partnership income or loss, to be filed in April on their .


are often taxed as partnerships. If this is the case, the partnership filing and payment regulations above apply, including the March 15, 2018, deadline for giving partners their .

If the multiple-member or S corporation, the due date for the tax status applied. 


A that has not filed a election may choose any convenient date as their year-end (usually a quarter-end date). For 2017 tax year, c are due and taxes are payable on the 15th day of the fourth month after the end of the company's fiscal (financial) year. For example, a corporation with a year-end date of December 31 must file and pay taxes by April 17, 2018.

Subchapter S Corporation 

Corporations which have filed a election are taxed on the individual income tax returns of the owners. The is filed on Form 1120-S, and the individual owners receive a showing their distributions from the corporation. 

An S corporation must usually take a calendar year end date (December 31) unless the corporation can establish a reasonable business purpose for a different date. The filing date and tax return due date are the same as for other corporations (March 15, 2018, for a 2017 December 31 tax year end.) 

For More Information on Other Tax Return Deadlines

Tax Planning at The Balance has information on tax deadlines for 2017 tax returns for all types of returns, including changes to other types of tax returns. 

Source for 2016 due date changes: