The March 16 Deadline Most Business Owners Forget, And Why It Matters More Than April 15
Steve PerryPublished on: 10/03/2026
For many partnerships and S corporations, March 16 matters more than April 15 because it controls K-1 timing, extensions, owner returns, and early penalty exposure.
irstaxtaxesrepresentationMarch 16 business tax deadlinepartnership tax return due dateS corporation tax return deadlineForm 1065 due dateForm 1120-S due dateForm 7004 extension for businessesSchedule K-1 deadlineSchedule K-3 deadlinebusiness tax extension deadlinewhy March 16 matters more than April 15late filed partnership returnlate filed S corporation returnSteve Perry EA IRS resolution expertBooks Taxes and More business tax help