Form CT-400, Estimated Tax for Corporations
E-file options
- Web File Form CT-400 directly from your Business Online Services account—it’s FREE.
- E-file Form CT-400. See Approved software developers for corporation tax e-file.
Benefits include:
- automatic calculation of amounts due
- scheduled payments (up to the due date)
- instant filing confirmation
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E-file mandate
Businesses
If you are viewing this page on your computer, then you're probably required to e-file Form CT-400. You must electronically file Form CT-400 if you:
- do not use a tax professional to file;
- use a computer to prepare, document, or calculate your tax forms; and
- have broadband Internet access.
If you file by paper and meet the above conditions, you are subject to penalties.
Tax Professionals
See Who the tax preparer e-file mandate applies to.
If you don't meet the above conditions
Continue to paper Form CT-400, Estimated Tax for Corporations (instructions), and see how to avoid common corporation tax filing errors.
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