What planning should small corporations consider by April 15?

by | Feb 28, 2026 | AI Tax Answer Library

Here’s what HIVE AI had to say about “What planning should small corporations consider by April 15?”:

April 15 items small corporations commonly need to have squared away (April 15, 2026)

C corporation (Form 1120) deadline and extension mechanics

  • Calendar-year C corporations generally have an income tax return due date of April 15 following the close of the tax year (so a 2025 calendar-year Form 1120 is due April 15, 2026). 6
  • If more time is needed to file, the key point is that an extension extends the filing deadline but does not automatically extend the time to pay (interest/penalty exposure can still apply if tax isn’t paid by the original due date). 1

Corporate estimated tax (for tax year 2026)

  • For a calendar-year corporation, estimated tax installments are due April 15, June 15, September 15, and December 15 of the taxable year. 7 2

Retirement plan contribution timing (deductibility cutoff can track the return due date, including extensions)

  • For certain small-business retirement plan contributions, deductibility can depend on making the contribution by the due date (including extensions) of the employer’s federal income tax return for that year. 3

“Due date (including extensions)” elections that can ride on the timely filed corporate return

  • Start-up and organizational cost elections are generally made on the return filed by the due date (including extensions) for the year the active trade or business begins; if missed, the instructions describe a limited amended-return window to make the election. 4

Foreign account reporting overlap (if the corporation has foreign financial accounts)

  • The FBAR (FinCEN Form 114) due date is April 15, with an automatic extension to October 15 if the April deadline is missed (no separate extension request needed). 5

Disaster-relief postponements (only if the corporation is in a covered disaster area)

  • If the IRS grants postponement relief under section 7508A for your location, it can postpone filing and payment obligations, and can interact with an already-filed extension (the later of the postponement end date or the extended due date generally controls for filing). 1

If you tell me whether you mean a C corporation (Form 1120) or an S corporation (Form 1120-S), I can narrow this specifically to what is actually due by April 15 for that entity type.

Sources

1 – IRS.gov – FAQs for disaster victims
2 – IRC § 6655(c)
3 – IRS – Publication 560 Retirement Plans for Small Business (SEP, SIMPLE and Qualified Plans)
4 – IRS.gov – Instructions for Form 1120-S (2024)
5 – IRS Newsroom – IR-2022-73
6 – 3.12.16 Corporate Income Tax Returns
7 – Instructions for Form 1120-S (2025)


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