Delaware

State of Delaware Business Income Tax Extensions

E-file an IRS business tax extension with TaxExtension.com

General Instructions

Corporations

Delaware corporate income tax returns are due by the 1st day of the 4th month after the end of the tax year (April 1 for calendar year taxpayers). If you cannot file by that date, you can request a state tax extension. A Delaware business extension will give you 6 extra months to file your return, which moves the deadline to October 1.

A state tax extension only gives you more time to file, not more time to pay. You are still expected to pay your Delaware tax liability by the original deadline of your return (April 1). Failing to file and/or pay on time will result in penalties and interest charges.

Use Form 1100-EXT (Corporation Income Tax Request for Extension) to apply for a Delaware tax extension. If you are making a payment with your extension, use Form 1100T-EXT (Corporate Request for Extension Voucher).

If you have a valid 6-month Federal tax extension (IRS Form 7004), you will automatically receive a 6-month Delaware tax extension. In that case, do not submit a separate state extension request to the Delaware Division of Revenue. Just remember to attach a copy of Form 7004 to your Delaware return when it’s filed.

S Corporations

The State of Delaware offers a 6-month tax extension for its S corporation income tax return. Use Form 1100S-EXT (S Corporation Income Tax Request for Extension) to apply for a Delaware tax extension. If you are making a payment with your state extension, use Form 1100P-EXT (S Corporation Request for Extension Voucher). Make sure to submit your Delaware extension request on or before the original due date of your return.

Partnerships

Delaware partnership tax returns are due by the 30th day of the 4th month after the end of the tax year (April 30 for calendar year taxpayers). To get a state tax extension, you must submit a copy of a valid Federal extension (IRS Form 7004) to the Delaware Division of Revenue by the original filing deadline of your return (April 30). The extended due date for your Delaware tax return will then be the same as the extended deadline for your Federal return (September 15 for most taxpayers). A photocopy of your IRS-approved Federal extension must be attached to your Delaware tax return when it’s filed.

 

Delaware Division of Revenue, Online Services: revenue.delaware.gov/services/online_svcs

For more information, please visit the Delaware Division of Revenue website: revenue.delaware.gov

Delaware State Income Tax Extension Forms

 

Form 1100-EXT (Corporation Income Tax Request for Extension): revenue.delaware.gov/services/current_bt/14_1100_ext.pdf

Form 1100-T-EXT (Corporate Request for Extension Voucher): revenue.delaware.gov/services/current_bt/14_1100T-EXT.pdf

Form 1100S-EXT (S Corporation Income Tax Request for Extension): revenue.delaware.gov/services/current_bt/14_1100s_ext.pdf

Form 1100-P-EXT (S Corporation Request for Extension Voucher): revenue.delaware.gov/services/current_bt/14_1100P-EXT.pdf

 

Mail Form 1100-EXT, Form 1100T-EXT, Form 1100S-EXT, or Form 1100P-EXT to the following address:

Delaware Division of Revenue

P.O. Box 8751

Wilmington, DE  19899-8751