Delaware State Business Tax Extension

For Corporation

The businesses operating (as C Corporation) in Delaware need to
file Form 1100-T-EXT with the state to obtain a 6-month extension of time to file their business income tax return with
the state.

• Form 1100-T-EXT - Request for Six-Month Extension to File Delaware Corporation Income Tax Return.

For S Corporation

The businesses operating ( S-Corporation) in Delaware need to file Form 1100-P-EXT with the state to obtain a 6-month extension of time to file their business income tax return with
the state.

• Form 1100-P-EXT - Request for Six-Month Extension to File Delaware Corporation Income Tax Return.

For Partnership

The businesses operating (as Partnership) in Delaware need to file Federal Extension with the state to obtain a 6-month extension of time to file their business income tax return with
the state.

For Fiduciaries

Businesses operating (as a Fiduciary) in Delaware are required to file Form 400-EX with the state to obtain a 6-month extension of time to file their business income tax return with the state.

• Form 400-EX - Request for 5 ½ Month Extension to File Delaware Corporation Income
  Tax Return.

Delaware Corporate Tax Extension

Delaware Corporate Tax Extension Form 1100-T-EXT is due by the 15th day of the 4th month following the end of the corporation
reporting period.

For corporations operating on a calendar year, this deadline is on
April 15.

To file an extension for Form 1100, apply for an extension using Form
1100-T-EXT on or before the same date the business tax return is due.

Form 1100-T-EXT grants an automatic 6-month extension of time to file
Form 1100.

Delaware S-Corporation Tax Extension

Delaware S- Corporation tax extension
Form 1100-P-EXT is due by the 15th day of the 3rd month following the end of the corporation reporting period.

For corporations operating on a calendar year, this deadline is on
March 15.

To file an extension for Form 1100-S,apply for an extension using Form
1100-P-EXT on or before the same date the business tax return is due.

Form 1100-P-EXT grants an automatic 6-month extension of time to file
Form 1100-S.

Delaware Partnership Tax Extension

Delaware State Partnership Tax Extension is due by the 15th day of the third month after the end of the partnership reporting period.

For businesses operating as partnerships on the calendar year, this deadline is on
March 15.

To file an extension for Form 300, apply for an extension using Federal Extension Form on or before the same date the partnership tax return is due.

Extension of time to file returns may be obtained by submitting a copy of the Federal extension application on or before the due date of the partnership return. A photocopy of the approved Federal extension MUST be attached to the return when filed. The approved Federal extension will extend the due date of the Delaware return to the same date as your Federal extension
due date.

Delaware Fiduciary Tax Extensions

The Delaware Fiduciary Tax Extension Form 400-EX is due by the last day of the 4th month following the end of the fiduciary
reporting period.

For Fiduciaries operating on a calendar year, this deadline is on April 30.

To apply for an extension of time to file Form 400, file Form 400-EX on or before the original deadline that the business tax return is due.

Form 400-EX grants an automatic 5 ½ month extension of time to
file Form 400.

You can choose to pay your balance due along with your return by using any one of the following options:

• Payment of the anticipated liability must be made with the
  extension request.
• EFT - Electronic Funds Transfer (use https://revenue.delaware.gov/services/BusEFT/BusEft.shtml u to make EFT payments)
• Check or money order - Make checks payable to the Delaware Department of Revenue. Include the taxpayer’s EIN on the front of the check or money order. Include the check or money order with the extension request.