Tax Due Dates.

March 2026

March 15:

  • S Corporation (Form 1120-S) tax returns due

  • Partnership (Form 1065) tax returns due

  • Extension deadline for S Corps & Partnerships (Form 7004)

April 2026

April 15:

  • Individual tax returns due (Form 1040)

  • C-Corporation tax returns due (Form 1120)

  • Q1 estimated tax payment due for individuals & businesses

  • Extension deadline for individual and C-Corp returns

  • IRA & HSA contributions deadline for the prior tax year