The Delaware Other State Tax Credit allows resident and part-year residents to claim a credit for income taxes paid to another state on income that is also included in Delaware taxable income. This credit is designed to prevent double taxation on the same income. However, taxes paid to political subdivisions (such as city wage taxes or county taxes) cannot be claimed as a credit. The District of Columbia is treated as a “State” for this credit and is eligible.
Eligibility and Requirements
If you are a resident of Delaware (or elect to be taxed as a resident) and pay income tax to another state on income earned in that state that is also included in your Delaware taxable income, you may claim a credit against your Delaware income tax.
The credit is limited to the smallest of:
- The Delaware tax liability.
- The net income tax due and paid to the other state after the application of all allowable credits.
- The portion of the Delaware tax attributable to the income taxed by both Delaware and the other state.
Documentation and Filing Requirements
- Claimants must attach a signed copy of the income tax return filed with the other state(s) to their Delaware return.
- Delaware will share return information with the other state(s) for which the credit is claimed.
- Do not include city or county taxes paid directly to local governments.
- If you are claiming a credit for taxes paid to more than one state, you must complete Form PIT-RSS Schedule I and attach it to your resident return.
- Add reference to Worksheet for Line 28 can be found in PIT-RES instructions
Worksheet for Line 28 (Credit for Taxes Paid to Another State – Form PIT-RES)
- Line 1: Enter adjusted gross income from the other state's income tax return.
- Line 2: Enter Delaware adjusted gross income from Line 12 of Form PIT-RES.
- Line 3: If Line 1 is less than Line 2, divide Line 1 by Line 2 and enter the result. If Line 1 is greater than Line 2, enter 100%.
- Line 4: Enter the amount from Line 24 of Form PIT-RES.
- Line 5: Multiply Line 3 by Line 4.
- Line 6: Enter income taxes paid to the other state, net of credits. Do not include city wage taxes or county taxes paid directly to a county.
- Line 7: Enter the smaller of Line 5 or Line 6. This is your allowable credit. Enter this amount on Line 28 of Form PIT-RES.
Source:
Delaware Non-Resident Income Tax Return Instructions (2025)
Delaware Resident Income Tax Return Instructions (2025)
Disclaimer: Always verify details with the official forms and instructions from the Delaware Division of Revenue or your state’s Department of Revenue. For complex situations, consult a CPA or tax attorney.