Delaware Income Tax Filing Deadlines by Tax Year

Delaware state income tax returns for the current tax year can be prepared and e-filed now along with an IRS or federal tax return (or you can learn how to only prepare and eFile a Delaware state return). Find IRS or federal tax return deadline details.

Delaware Income Tax Filing Deadlines

The majority of deadlines listed here are for Tax Year 2023; some apply to upcoming years and some are IRS or federal deadlines.

Deadline
Type
Description
April 30, 2024
Tax Year 2023
Income Tax Return
Prepare and e-File an IRS (Due Date April 18, 2023) and Delaware State Income Tax Return (Due Date April 30, 2024) until October 15, 2024 - eFileIT.
April 30, 2024
2023 Income Tax Extension
October 15, 2024
Tax Year 2023
Income Tax Return after the April 30, 2024 Delaware Tax Extension
Last day to e-File a 2023 Delaware State Income Tax Return for Tax Extension Filers and late eFilers. You can only e-File (to file by paper see below) Delaware Income Tax Return together with an IRS Tax Return - eFileIT.
October 15, 2024 via mail-in Forms.
Forms incl. Mailing Address are listed below.
Tax Year 2023
Income Tax Return after the April 30, 2024 Delaware Tax Extension
Deadline for taxpayers who got a DE Tax Extension to file their Delaware Income Tax Return by mail-in Forms - the Forms incl. mailing addresses are listed below - is October 15, 2024. (Optionally, the eFileIT deadline is Oct. 15, 2024). Instructions on how to only - without the IRS return - prepare and file a Delaware State Income Tax Return on eFile.com.
Tax Amendment for all Tax Years
IRS Due Dates
IRS Tax Return, Extension, Amendment Deadlines
2023, 2024, etc.
Other State Tax Return, Extension, Amendment Deadlines
Select respective State Tax Return Deadlines.
2023, 2024, etc.
IRS Federal Income Tax Return, Amendment, Extension Deadlines
April 15, 2025
2021 Delaware Income Tax Return Refund
The last day to file and claim your 2021 Delaware Income Tax Return. This deadline does not apply if you owe Income Taxes.After that date your 2021 tax refund will expire. See details on unclaimed refunds.
April 15, 2026
2022 Delaware Income Tax Return Refund
The last day to file and claim your 2022 Delaware Income Tax Return. This deadline does not apply if you owe Income Taxes. After that date your 2022 tax refund will expire. See details on unclaimed refunds.
April 15, 2027
2023 Delaware Income Tax Return Refund
The last day to file and claim your 2023 Delaware Income Tax Return. This deadline does not apply if you owe Income Taxes. After that date your 2023 tax refund will expire. See details on unclaimed refunds.

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