A calendar-year C corporation extends Form 1120 by filing Form 7004 with form code 12 by April 15. The extension is six months, to October 15. Unlike pass-through entities, a C corporation owes its own tax, and the extension does not extend the payment.
Estimating the payment
Part II of Form 7004 asks for tentative total tax, payments already made, and balance due. The balance is due with the request. Underpay and the corporation owes interest and the failure-to-pay penalty from April 15. The failure-to-file penalty for a C corporation is the same 5 percent per month structure that applies to individuals, with the same minimum penalty after 60 days.
Fiscal years
A C corporation with a fiscal year files by the 15th day of the fourth month after year end and extends six months. The exception is a June 30 year end: due September 15, with a seven-month extension to April 15.
Estimated payments
C corporations make estimated payments on the 15th day of the fourth, sixth, ninth, and twelfth months of the tax year. An extension has nothing to do with those.
Common mistake
Filing the extension with a zero balance because the return is not done. The IRS treats an estimate that is not made in good faith as grounds to void the extension. Use last year's tax as the floor.
Ready to file it?
You can file a business extension (Form 7004) online in a few minutes with TaxExtension.com, an IRS-authorized e-file provider operated by our publisher. The extension is automatic; the payment is still due on the original date.
Sources
- IRS, About Form 7004
- IRS, Instructions for Form 1120