Guides

Ten pages on federal filing dates, penalties, e-filing and elections for Form 1065, Form 1120-S, and Form 1120. All 2027 dates are labelled expected. Nothing here is a filing position.

• Who Files Form 1065 or 1120-S by March 15, 2027
  Partnerships and multi-member LLCs file Form 1065, S corporations Form 1120-S. For calendar-year entities the due date is expected on March 15, 2027.
• Form 7004: 6-Month Extension for 1065 and 1120-S
  Form 7004 gives an automatic 6-month extension to file 1065 and 1120-S (expected September 15, 2027), but it does not extend the time to pay any tax.
• Schedule K-1 Due Date for Partners and Shareholders
  Schedules K-1 are generally due to partners or shareholders by the return due date, expected March 15, 2027 for calendar-year entities. Penalties.
• Late 1065 and 1120-S Penalty: $260 per Person (2027)
  Late 1065 and 1120-S penalty: $255 per person per month for returns due 2026, $260 for returns due 2027 (Rev. Proc. 2025-32), up to 12 months.
• LLC Tax Classification: Which IRS Return Applies?
  An LLC's federal return depends on how it is classified: partnership (1065), S corporation (1120-S), or disregarded entity. What the IRS instructions say.
• S Corp vs C Corp Deadlines 2027: 1120-S vs 1120
  For calendar-year entities, 1120-S is expected due March 15, 2027 and Form 1120 April 15, 2027. Extension dates and what differs, from IRS instructions.
• Form 1065 E-Filing: 10-Return Rule and 100+ Partners
  The 1065 instructions require e-filing if the partnership files 10 or more returns of any type, or has over 100 partners. Waiver and limits.
• Form 2553 and Form 1120-S: What Must Be True First
  Form 1120-S requires an S election: Form 2553 filed, accepted by the IRS and still in effect. Checklist with the 2 months 15 days rule and late relief.
• State Filings: Why No State Date Is Listed
  Federal return dates on this site are not state annual-report or franchise-tax dates. Those obligations vary, and this site does not list a state deadline.
• Tools and Resources, With No Outbound Links
  What the on-site checker does, how the IRS describes e-file for these returns, and why this page names no formation, registered-agent, or bookkeeping vendor.