Delaware — Personal Income Tax

Delaware imposes a personal income tax on residents and nonresidents under Title 30, Chapter 11 of the Delaware Code. The Department of Finance, Division of Revenue, administers the tax.

Source: 30 Del. C. § 1101 et seq.

## Residents

Every Delaware resident must file a personal income tax return if the resident either (a) is required to file a federal tax return, or (b) has Delaware adjusted gross income (after modifications) that exceeds the filing thresholds.

The filing thresholds for residents vary by age and filing status. For tax year 2025 (returns filed in 2026), residents must file if their Delaware adjusted gross income exceeds the following amounts:

• Under age 60: Single $9,400 | Married filing jointly $15,450 | Married filing separately $9,400
• Age 60 to 64: Single $12,200 | Married filing jointly $17,950 | Married filing separately $12,200
• Age 65 and over or blind: Single $14,700 | Married filing jointly $20,450 | Married filing separately $14,700
• Filing as a dependent on another person's return: $5,250 (all ages)

These thresholds have remained unchanged since they were set for tax years beginning after December 31, 1999. Delaware has not indexed these thresholds for inflation or otherwise adjusted them through the 2025 tax year.

Source: Delaware Division of Revenue, Form PIT-RES Instructions for 2025

Residents report their entire taxable income, which is federal adjusted gross income with Delaware-specific modifications, less deductions and personal exemptions.

Source: 30 Del. C. § 1105

## Nonresidents

Every nonresident must file a Delaware tax return to report all income earned within the state. Delaware-source income for nonresidents includes only income attributable to (1) employment or personal services performed in Delaware, or (2) ownership or disposition of any interest in real or tangible personal property located in Delaware. This includes wages, business income, capital gains, rents, royalties, partnerships, farm income, and any other income derived from a Delaware source.

Source: Delaware Division of Revenue, Form PIT-RES Instructions for 2025

Source: 30 Del. C. § 1121 and § 1122

Interest, dividends, and pensions are not treated as Delaware-source income for nonresidents, even if attributable to Delaware investments or prior Delaware employment.

Source: Delaware Division of Revenue, Form PIT-RES Instructions for 2025

Compensation paid by the United States for service in the armed forces performed by a nonresident does not constitute Delaware-source income.

Source: 30 Del. C. § 1124(g)

## Part-Year Residents

Part-year residents have the option of filing either as a resident or as a nonresident. Filing as a nonresident reduces final liability because it is prorated according to the taxpayer's ratio of Delaware-source income to total income. Filing as a resident allows the taxpayer to use certain tax credits (such as the child care credit) that are not available to nonresidents.

Source: Delaware Division of Revenue, Form PIT-RES Instructions for 2025

Source: 30 Del. C. § 1125

Delaware imposes a graduated personal income tax with rates and brackets set in Title 30, Section 1102 of the Delaware Code. For tax years through 2025, tax is calculated across seven brackets, with rates ranging from 0% to 6.60%. For tax years beginning after December 31, 2025 (i.e., returns filed for 2026 and onward), Delaware amended its statute to add two new upper income brackets and increased the top marginal rate. The new structure is as follows:

Delaware personal income tax rates for tax year 2026 and after:

• Up to $2,000: 0%
• $2,001–$5,000: 2.2%
• $5,001–$10,000: 3.9%
• $10,001–$20,000: 4.8%
• $20,001–$25,000: 5.2%
• $25,001–$60,000: 5.55%
• $60,001–$125,000: 6.60%
• $125,001–$250,000: 6.75% (new bracket)
• $250,001 and above: 6.95% (new bracket and new top rate)

These changes were adopted under House Bill 13, enacted in June 2024 and effective for tax years beginning after December 31, 2025. For prior years, the highest rate was 6.60% on taxable income above $60,000.

Source: 30 Del. C. § 1102 Source: Delaware HB 13 (2024)

Delaware allows resident individuals to claim a standard deduction in lieu of itemizing deductions. The standard deduction is $3,250 for single filers and $6,500 for married couples filing jointly ($3,250 each for married filing separately). Taxpayers age 65 or older, or who are blind, may claim an additional standard deduction of $2,500.

Source: 30 Del. C. § 1108 and Delaware Division of Revenue, 2024 Estimated Tax Instructions

Delaware personal income tax returns are due on or before the thirtieth day of the fourth month following the close of the taxpayer's taxable year. For calendar-year taxpayers, this means returns and any tax due must be filed and paid by April 30. If April 30 falls on a weekend or legal holiday, the deadline shifts to the next business day. An extension to file may be requested by filing Form PIT-EXT by the original April 30 due date, which extends the filing deadline to October 15; however, the extension applies only to filing, not to payment—any tax owed must still be paid by April 30 to avoid penalties and interest.

Source: 30 Del. C. § 1168

Delaware allows resident individuals a personal credit of $110 for each personal exemption claimed for federal income tax purposes. An additional $110 credit is allowed for each resident person age 60 or over. The credit reduces tax liability dollar-for-dollar but cannot exceed the tax otherwise due under the chapter, making it nonrefundable.

Source: 30 Del. C. § 1110

Delaware law requires every employer that maintains an office or transacts business within Delaware and makes payment of wages or other remuneration taxable under Chapter 11 to a resident or nonresident individual to withhold Delaware personal income tax from those wages if the wages are subject to withholding under the Internal Revenue Code. The employer must withhold an amount substantially equivalent to the tax reasonably estimated to be due from the employee for the calendar year.

Scope of withholding obligation. The Delaware Code does not specifically define "wages" or "other remuneration" subject to withholding. Delaware withholding is required if the wages or other remuneration are subject to withholding under the Internal Revenue Code. This creates a federal conformity rule: if federal withholding applies, Delaware withholding applies. This covers, for example, wages paid for personal services, but generally does not extend to items not subject to federal withholding such as certain contractor payments.

Resident vs. nonresident employees. The compensation of a Delaware resident is subject to withholding if the personal services are performed as an employee in the conduct of business of an employer in Delaware. The compensation of a nonresident is subject to withholding to the extent that it is compensation for personal services performed in Delaware as an employee in the conduct of business of an employer in Delaware. Employers engaged in business outside Delaware who employ Delaware residents working in another state are not required to withhold Delaware income tax on those employees, though they may voluntarily do so under Division of Revenue-approved procedures.

Withholding method. Employers may use the withholding tax tables published by the Division of Revenue or any alternate formula approved by the Division. The employer must withhold at a rate designed so that no tax is estimated to be due on the wages paid when the employee files the personal income tax return. The Division will approve an alternate formula that considers the allowable standard deduction and tax credits claimed by the employee, using the tax rate schedule on the balance of the wages paid.

Filing frequency. Employers file and pay withheld taxes on a quarterly, monthly, or eighth-monthly basis, determined by a "lookback period" that measures the employer's aggregate withholding during the twelve-month period from July 1 through June 30 immediately preceding the calendar year for which the frequency is determined. Under 30 Del. C. § 1154(a), as amended and incorporating annual threshold adjustments under 30 Del. C. § 515:

• Quarterly filers: employers whose aggregate withholding during the lookback period did not exceed the applicable threshold ($6,020 for calendar year 2026).
• Monthly filers: employers whose aggregate withholding during the lookback period exceeded $6,020 but did not exceed $33,460 for calendar year 2026, or employers with no employees in Delaware during the lookback period.
• Eighth-monthly filers: employers whose aggregate withholding during the lookback period exceeded $33,460 for calendar year 2026.

These thresholds are indexed annually. Employers with no prior withholding record file monthly until the next lookback period determines a different frequency.

Due dates. Quarterly filers must file a return and pay over taxes by the last day of the month following the close of each calendar quarter. Monthly filers must file and pay by the fifteenth day of the month following the end of each month. Eighth-monthly filers must file and pay within three working days following the end of any deposit period during which the employer made a payment subject to withholding. Each month is divided into eight deposit periods ending on the 3rd, 7th, 11th, 15th, 19th, 22nd, 25th, and last day of the month. If a due date falls on a weekend or state holiday, the deadline shifts to the next regular working day.

Annual reconciliation. Every employer required to withhold must file an annual withholding tax reconciliation form, accompanied by copies of Forms W-2, on or before January 31 of the following year or within 30 days from the date on which the last payment of wages was made if employment is terminated during the year. Delaware does not require quarterly reconciliation forms; only the annual reconciliation is accepted.

Electronic filing and payment. Any employer required under IRC § 6302 to deposit federal employment taxes by electronic funds transfer must deposit Delaware withholding taxes by electronic funds transfer. Employers required to file W-2 or 1099-MISC forms electronically for federal purposes must also file those forms electronically for Delaware.

Employer liability. Every employer required to deduct and withhold tax under Chapter 11 is made liable for such tax. For purposes of assessment and collection, any amount required to be withheld and paid over to the Division of Revenue, and any additions to tax, penalties, and interest with respect thereto, are considered the tax of the employer. Any amount of tax actually deducted and withheld is held to be a special fund in trust for the state. If an employer fails to withhold as required and the employee later pays the tax, the employer is relieved from collecting the tax itself but not from liability for penalties and interest.

Source: 30 Del. C. § 1151 Source: 30 Del. C. § 1154 Source: 30 Del. C. § 1155 Source: Delaware Division of Revenue, Employer's Guide (Withholding Regulations and Employer's Duties) Source: Delaware Division of Revenue, Lookback Period Source: Delaware Division of Revenue, Withholding Tax FAQs

Delaware requires resident and nonresident individuals to make quarterly estimated income tax payments when their estimated tax for the year can reasonably be expected to exceed $800. This requirement applies to both residents (on their entire income) and nonresidents (on their Delaware-source income).

Declaration and threshold

Under 30 Del. C. § 1169(a), every resident and nonresident individual or trust must make a declaration of estimated tax for the taxable year "if the estimated tax can reasonably be expected to exceed $800." The statute directs that the declaration be in such form as the Director of Revenue may prescribe. The threshold is absolute—if estimated tax exceeds $800, a declaration is required.

Quarterly installment due dates

Estimated tax may be paid in full when the declaration is filed, or in equal installments on the remaining quarterly payment dates. Delaware's Division of Revenue publishes four installment due dates for calendar-year taxpayers:

• First installment: April 30
• Second installment: June 15
• Third installment: September 17
• Fourth installment: January 15 of the following year

The first installment must accompany the declaration. The last installment must be mailed no later than January 15 of the following year. Payment of the estimated income tax, or any installment thereof, is considered payment on account of the income tax imposed for the taxable year under 30 Del. C. § 1170(c).

Safe harbor rules to avoid underpayment penalty

Delaware law imposes a penalty for underpayment of estimated tax installments, but the Division of Revenue's official instructions specify two alternative safe harbors. According to the Form 200-ES Instructions, the penalty does not apply if each installment is paid on time and satisfies one of the following:

1. Current-year safe harbor: At least 90 percent of the amount due on the income tax return for the taxable year (66⅔% for farmers and fishermen); or

1. Prior-year safe harbor: 100% of the tax shown on the prior year's return—or 110% if the federal adjusted gross income for the prior tax year exceeded $150,000 ($75,000 if married filing separately).

Payment of estimated tax is not required if the taxpayer had no tax liability for the preceding taxable year.

Underpayment penalty rate

A penalty of 1½% per month or fraction thereof may be imposed on the underpayment of any installment of estimated tax, except where the safe harbor requirements are satisfied. The Form 200-ES Instructions state that the underpayment penalty may be waived if the underpayment is due to casualty, disaster, or other unusual circumstances.

Amendment of declaration

Delaware permits a taxpayer to amend a declaration of estimated tax as prescribed by the Director of Revenue under 30 Del. C. § 1169(d). The current Form 200-ES Instructions clarify that it is no longer required to file a formal amended form (Form 200-ES (amended)). Instead, if changes in income, exemptions, or deductions cause a substantial increase or decrease in estimated tax, the taxpayer should adjust the remaining installments by revising the amount entered on the voucher for each remaining due date.

Source: 30 Del. C. § 1169

Source: 30 Del. C. § 1170

Source: Delaware Division of Revenue, Form 200-ES Declaration of Estimated Income Tax Instructions

Delaware imposes separate penalties for failure to file a personal income tax return on time and for failure to pay tax on time, plus interest on any unpaid balance. These provisions apply to personal income tax returns filed after the due date (April 30 for calendar-year taxpayers) or after any approved extension deadline.

Failure-to-file penalty

Under 30 Del. C. § 534(a), if a taxpayer fails to file a return by the due date (determined with regard to any extension of time for filing), unless the failure is due to reasonable cause and not willful neglect, a penalty of 5% per month (or fraction thereof) of the balance due is imposed. The penalty accrues for each month or part of a month that the return remains unfiled, up to a maximum of five months (50% total). This penalty applies to late-filed returns that show a balance due.

The statute permits the Director of Revenue to waive the penalty if the taxpayer demonstrates that the failure was due to reasonable cause and not willful neglect.

Failure-to-pay penalty

Under 30 Del. C. § 534(b), if a taxpayer fails to pay the tax shown on a timely filed return, a penalty of 1% per month (or fraction thereof) is imposed on the unpaid tax liability, not to exceed 25% in total. This penalty applies when the return is filed on time but the tax shown on the return is not paid in full by the due date.

The failure-to-pay penalty is separate from and in addition to the failure-to-file penalty. A return filed late with a balance due will typically incur both penalties (5% per month for late filing and 1% per month for late payment), subject to their respective caps.

Interest on underpayment

Under 30 Del. C. § 533(a), any unpaid tax—including tax required to be withheld and including penalties and additions to tax—bears interest at the rate of 0.5% per month (or fraction thereof) from the last date prescribed for payment until the date the tax is paid. This interest rate applies to personal income tax liabilities under Chapter 11. After the assessment becomes final, the interest compounds monthly.

Interest accrues from the original due date (determined without regard to any extension of time for filing or payment) and continues until the liability is paid in full. No interest is imposed if the amount due is less than $1.00. Interest does not apply to underpayment of estimated tax under 30 Del. C. § 1170; estimated tax underpayment is subject to a separate 1½% per month penalty as described in the estimated-tax-payments section of this guide.

Interaction of penalties and interest

The failure-to-file penalty (5% per month, up to 50%) and the failure-to-pay penalty (1% per month, up to 25%) are calculated on the unpaid tax balance. Interest at 0.5% per month is then calculated on the unpaid tax plus any penalties. All three charges accrue simultaneously on a late-filed return with an unpaid balance.

Reasonable cause exception

Both the failure-to-file and failure-to-pay penalties may be waived or abated if the taxpayer shows that the failure was due to reasonable cause and not willful neglect. The statute does not define "reasonable cause," but the Division of Revenue has discretion to grant relief where circumstances beyond the taxpayer's control caused the delay. Interest under § 533 is not subject to a reasonable-cause waiver and accrues automatically on any unpaid amount.

Presidentially-declared disaster relief

Under 30 Del. C. § 533(i), if the U.S. Secretary of the Treasury extends the time for filing and paying federal income tax for taxpayers in a Presidentially-declared disaster area under IRC §§ 6081 and 6161, the Delaware Director of Revenue will abate both the interest under § 533 and the penalties under § 534(a) (failure to file) and § 534(b) (failure to pay) for the same period on the taxpayer's Delaware personal income tax.

Source: 30 Del. C. § 534 Source: 30 Del. C. § 533 Source: Delaware Division of Revenue, Personal Income Tax FAQs

Delaware allows resident individuals a credit against their Delaware personal income tax for income taxes paid to another state or the District of Columbia on income that is also subject to Delaware tax. The credit prevents double taxation when a Delaware resident earns income in another jurisdiction that taxes the same income.

Who qualifies for the credit

Under 30 Del. C. § 1111(a), a Delaware resident individual is allowed a credit against the Delaware tax for "the amount of any income tax imposed for the taxable year by another state of the United States, or the District of Columbia, on income derived from sources therein which is also subject to tax under this chapter." The credit is available only to residents; nonresidents cannot claim this credit because they are taxed only on Delaware-source income.

The income must be (1) taxed by the other state, (2) derived from sources in that other state, and (3) also included in the resident's Delaware taxable income. The credit applies only to state-level income taxes; it does not apply to local government income taxes (such as city or county wage taxes) or to foreign country income taxes.

Calculation: the "lesser of" limitation

The credit is subject to a statutory limitation designed to ensure that Delaware does not give away more tax revenue than it would have collected on the out-of-state income. Under 30 Del. C. § 1111(b), "the credit allowable under this section, with respect to the income tax imposed upon the taxpayer for the taxable year by each other taxing jurisdiction, shall not exceed the amount computed by multiplying the tax otherwise due under this chapter by a fraction, the numerator of which is the amount of the taxpayer's taxable income derived from sources in the other taxing jurisdiction (applying the rules of § 1122 of this title) and the denominator of which is the entire taxable income."

In practical terms, the credit is the lesser of:

1. The actual tax paid to the other state on the income from that state (after application of all credits in the other state, not including amounts paid to local jurisdictions within that state); or

1. The Delaware tax attributable to the out-of-state income, computed by multiplying the Delaware tax liability (before the other-state credit) by the ratio of (a) taxable income from the other state to (b) the taxpayer's entire taxable income.

This "lesser of" rule means that if the other state's tax rate is lower than Delaware's effective rate, the credit is capped at the amount actually paid to the other state. If the other state's rate is higher, the credit is capped at the Delaware tax that would have been due on that income, preventing the other state's higher tax from reducing Delaware tax on Delaware-source income.

The sourcing rules of 30 Del. C. § 1122 apply to determine what income is "derived from sources in the other taxing jurisdiction" for purposes of the numerator. Section 1122 generally sources income from personal services to the state where the services are performed, and income from real or tangible personal property to the state where the property is located. Interest, dividends, and pensions are not sourced to any state for nonresident taxation purposes under Delaware law, which means a Delaware resident who receives such income while living in Delaware and pays tax on it to another state (for example, because the resident was formerly domiciled there and the other state still claims them as a resident) may face practical issues claiming the credit, since the income may not be considered "derived from sources" in the other state under § 1122's rules.

Multiple states and required documentation

If a Delaware resident pays income tax to more than one state during the tax year, the credit is calculated separately for each state, and the resident must complete Delaware Schedule I and attach it to the Delaware resident return. The taxpayer must attach a signed copy of the income tax return filed with each other state in order to claim the credit. The Division of Revenue shares Delaware return information with the other states for which the credit is claimed.

District of Columbia is treated as a state

The statute explicitly includes the District of Columbia within the definition of "another state" for purposes of this credit. Taxes paid to D.C. on income derived from sources in D.C. qualify for the credit under the same rules as taxes paid to any U.S. state.

Source: 30 Del. C. § 1111

Source: 30 Del. C. § 1122

Source: Delaware Division of Revenue, Personal Income Tax FAQs

Delaware allows part-year residents to change their initial election—whether to file as a full-year resident or a nonresident—by filing an amended return using the alternative form. The election is originally made by the choice of return form (Form 200-01 for resident, Form 200-02 for nonresident). If a part-year resident wishes to change this election after filing, they may file an amended return on the appropriate alternative form (Form 200-01-X for resident or Form 200-02-X for nonresident). The amended return instructions expressly state: “Part-Year Residents may choose to file Form 200-01-X or Form 200-02-X,” thereby acknowledging that the Division of Revenue permits this change. There is no published Delaware statute, regulation, or Division of Revenue bulletin that imposes any special time limit for making this change, so the general statute of limitations for amended returns applies—generally three years from the original due date of the return or two years from the date the tax was paid, whichever is later. When changing the election, the taxpayer should complete and submit the full amended version of the correct form (not just a partial update or a written statement) and attach all supporting schedules and documentation.

Source: 30 Del. C. § 1125 Source: Delaware Division of Revenue, Form 200-02-X Instructions, p. 1 ("Part-Year Residents may choose to file Form 200-01-X or Form 200-02-X") Source: Delaware Division of Revenue, Form 200-01-X Instructions, p. 1 (general amended return rules and limitations)

Delaware law does not define an explicit “safe harbor” for estimated income tax, but the Division of Revenue’s instructions for Form PIT-RES and Form 200-ES use a tax liability threshold to determine when estimated tax payments and underpayment penalties apply. The key operative threshold is whether the taxpayer’s “tax liability after credits” for the previous year was below $800.

Threshold for estimated tax and penalty The Form PIT-RES Instructions for 2025 state: “You must make estimated tax payments if your tax liability, after credits, can reasonably be expected to exceed $800.” The Form 200-ES instructions confirm: “Individuals...must make estimated tax payments if you can reasonably expect your tax liability, after credits, for the year to be more than $800.” If tax liability after credits is less than $800, estimated payments are not required, and underpayment penalties will not be imposed.

What counts as 'tax liability after credits' Both instructions require taxpayers to determine tax liability “after credits,” but do not specify whether this refers only to nonrefundable credits or also includes refundable credits. The authoritative forms are silent on this question. Practitioners generally interpret the phrase to include all credits listed on the return, but primary source text does not expressly confirm treatment of refundable credits. No interpretive bulletin or published administrative ruling addresses this question as of this writing.

Application to prior-year nonfilers and nonresidents Neither the Delaware Code nor official guidance addresses situations where a taxpayer did not have a Delaware filing requirement in the prior year (such as newly arrived residents or new Delaware-source earners). The instructions and statutes are silent as to whether such taxpayers are treated as having “zero tax liability” for safe-harbor/penalty-trigger purposes or whether the prior year is simply disregarded.

Summary

• Delaware uses a current/prior year threshold requiring tax liability “after credits” to exceed $800 to trigger estimated tax payments and penalties.
• Credits are not distinguished by type; the instructions do not answer whether refundable credits count.
• Official sources do not use “safe harbor” language; this is an analytic term for the penalty threshold.
• Guidance is silent on the application to those who were not Delaware taxpayers in the prior year.

Source: Delaware Division of Revenue, Form PIT-RES Instructions for 2025, p. 2 Source: Delaware Division of Revenue, Form 200-ES Estimated Tax Instructions, p. 1

Delaware law, under 30 Del. C. § 1111, allows a resident a credit for income taxes paid to another state only on income "derived from sources therein" and taxed by both states. The Delaware sourcing rules under 30 Del. C. § 1122 generally do not treat interest, dividends, or pensions as sourced to another state for nonresidents. Thus, where a Delaware resident pays tax to another state on investment income because that state asserts continuing residency, and Delaware law does not recognize the income as sourced to that state, the credit is categorically unavailable for that income under the "derived from sources therein" test.

No published Division of Revenue regulations, bulletins, or administrative rulings provide for a facts-and-circumstances review or dispute mechanism that allows such income to qualify for the credit via equitable relief or alternative sourcing. The statute and official guidance require the income to meet Delaware’s sourcing rule for the credit to be available. If the income is not "derived from sources in" the other state as determined by Delaware law, the credit is not allowed—even if double taxation results from the other state's continued assertion of residency.

While taxpayers may contact the Division of Revenue regarding credit disallowance, there is no published state-level mechanism to contest the core sourcing determination or override the statutory criteria. No official Delaware publication, FAQ, or form instruction expands or alters this requirement as of June 2026.

Source: 30 Del. C. § 1111 Source: 30 Del. C. § 1122 Source: Delaware Division of Revenue, Personal Income Tax FAQs