Delaware corporate income tax return

File the Delaware corporate income tax return with the Delaware Division of Revenue by the 15th day of the 4th month after the fiscal year ends (April 15 for a calendar year) and pay any tax due. Most states follow the federal extension if one is filed.

When: By the 15th day of the 4th month after the fiscal year ends (April 15 for a calendar year).
Agency: Delaware Division of Revenue
Applies to: C corporations based in or operating in Delaware.
Source: revenue.delaware.gov, read October 22, 2026

Jay explains

Delaware taxes corporate income, so a C corporation doing business there files a state return with the Delaware Division of Revenue by the 15th day of the 4th month after the fiscal year ends (April 15 for a calendar year), the same day as the federal Form 1120. The state usually honors a federal extension to file, but not to pay. The form name and any minimum tax are on the state's site. A corporation formed in Delaware but based elsewhere, with no Delaware operations, files the annual report and franchise tax instead and owes no Form 1100.

Next dates

For a calendar year company. Shown as the agency states them; if a date falls on a weekend, file before it.

April 15, 2027
April 15, 2028

Also in Delaware

Delaware annual report and franchise tax Delaware foreign corporation annual report Delaware annual LLC tax Delaware annual partnership tax Delaware nonprofit annual report Delaware charitable solicitation registration: not required Delaware business license renewal Delaware gross receipts tax return Delaware franchise tax installment (if last year's tax was $5,000 or more)Delaware corporate estimated tax payment Delaware pass through entity return Delaware personal income tax return with business income

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What kind of organization is it?

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State of formation

Employees

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Where is it based? The state of the office, or of most of the people

Most Delaware companies are based in another state and owe that state's filings too. If that is you, pick it here.

More about the company: other states, payroll, dates, abroad

Company name

Date registered in each other state

Optional. Some states key their report to the day you registered there rather than your date of formation; without it, the formation date stands in and the calendar says so.

Who runs payroll?

Fiscal year ends in

Date of formation

Needed for states that key filings to the anniversary of formation.

Annual revenue

Some taxes start at a revenue threshold.

We pay independent contractors We offer a retirement plan (401(k), SIMPLE, SEP)

Outside the United States We hold a bank or financial account outside the US A person or company outside the US owns 25% or more of it We own 10% or more of a company outside the US We pay people or companies outside the US

Each adds the FinCEN or IRS form that comes with it: the FBAR, Form 5472, Form 5471, Forms 1042 and 1042-S.

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