CMP-EXT: Composite Return Extension (2024)
Delaware · Delaware Division of Revenue · Used for tax years 2024
Form CMP-EXT requests an automatic extension until October 15, 2025, to file a 2024 Delaware Composite Income Tax Return. It reports expected income tax liability, estimated tax payments, other payments and credits, and the balance due to be paid in full.
Who files this form
Form CMP-EXT is used to request an automatic extension of time to file a Delaware Composite Income Tax Return for tax year 2024.
When it's due
- Extension application deadline for tax year 2024: April 30, 2025.
- Requested extended filing date for the 2024 Composite Income Tax Return: October 15, 2025.
What you'll need
Have the following information ready to complete the form:
- Business name, mailing address and Employer Identification Number.
- Total income tax liability you expect to owe for 2024.
- Estimated tax payments, including prior-year overpayments allowed as a credit.
- Other payments and credits. The form refers to instructions for this line, but no instructions were provided.
- The signing officer’s title, email address and phone number.
How to file
Complete the business information and payment lines:
- Enter the total income tax liability you expect to owe on line 1.
- Enter estimated tax payments, including prior-year overpayments allowed as a credit, on line 2.
- Enter other payments and credits on line 3.
- Add lines 2 and 3 and enter the total on line 4.
- Subtract line 4 from line 1 to find the balance due on line 5. Pay that balance in full.
Have the officer sign and date the form and provide their title and contact information. Keep a copy for your records.
Mail the completed form with remittance payable to:
Delaware Division of Revenue
PO Box 830
Wilmington, DE 19899-0830
Common mistakes
- Forgetting to sign the form. The form specifically reminds you to sign.
- Not keeping a copy for your records.
- Cutting the page. The form states, “DO NOT CUT THIS PAGE.”
- Not paying the balance due in full, as directed on line 5.
Questions people ask
What does Form CMP-EXT request?
It requests an automatic extension until October 15, 2025, to file the 2024 Delaware Composite Income Tax Return.
When must I file the extension application?
For tax year 2024, the form must be filed by April 30, 2025.
Where do I include prior-year overpayments allowed as a credit?
Include them with estimated tax payments on line 2.
How do I calculate the balance due?
Add lines 2 and 3 to get line 4. Then subtract line 4 from line 1 to get the balance due on line 5. The form directs you to pay that balance in full.
Who signs the form?
The form has a signature line for an officer, along with fields for the date, officer’s title, email address and phone number.