For Delaware personal income tax purposes, individuals must file a Declaration of Estimated Tax if they expect to owe more than $800 in tax for the taxable year after accounting for withholding. This requirement applies to both residents and non-residents. The declaration must be filed and the first estimated tax payment made on or before April 30 for calendar-year taxpayers. Fiscal-year taxpayers must file and pay by the due dates prescribed for their fiscal tax year.
Filing Status and Joint Filings
- FILING STATUS 1 – SINGLE TAXPAYER: If you were single on December 31, 2025, consider yourself Single for the whole year and use Filing Status 1.
- FILING STATUS 2, 3, AND 4 – MARRIED TAXPAYERS You may file Joint, Separate, or Combined Separate Delaware returns.
- If you use Filing Status 4, you are in fact filing two separate returns which have been combined on the same form for convenience.
- NOTE: Generally, separate returns (filing status 3 or 4) will be advantageous if both spouses have Delaware adjusted gross income in excess of $9,400.
- If you elect to use Filing Status 3 or 4, both you and your spouse must compute your taxable income the same way.
- This means if one itemizes deductions, the other must itemize. If one takes the standard deduction, the other must take the standard deduction in computing taxable income.
- If you elect to use Filing Status 3, you must include your spouse’s name and taxpayer ID on your return.
- For Filing Status 3 or 4, you must each report your own income, personal credits, deductions, and one-half of the income derived from securities, bank accounts, real estate, etc., which are titled or registered in joint names.
- FILING STATUS 5 – HEAD OF HOUSEHOLD: If you filed as Head of Household on your federal return or qualify as certain married persons living apart, you may file as Head of Household on your Delaware return
WHO MUST FILE
- If you are a Full-Year Resident of the State, you must file a tax return for 2025 if, based on your Age/Status, your individual Delaware adjusted gross income (AGI) exceeds the designated filing threshold for the tax year.
- If you were a Part-Year Resident, you must file a Delaware tax return:
- If you had income from any source while a resident of Delaware, or
- If you had income from a Delaware source while you were a non resident of Delaware.
- If you are a Non-Resident who had gross income in 2025 from sources in Delaware, you must file a Delaware Tax return.
Source:
Form PIT-UND.pdf
Form PIT-BIN.pdf
Disclaimer: Always verify details with the official Delaware Division of Revenue forms and instructions for the current tax year. For complex situations, consult a CPA or tax attorney.