Delaware State Income Tax Filing: Forms, Deadlines & Requirements

1. What Is Delaware State Income Tax Filing?

Delaware State Tax Filing is the annual requirement to report income earned during the tax year to the My Delaware Taxes. This filing applies to residents, part-year residents, and nonresidents who have Delaware-source income.

Delaware state income tax is separate from federal income tax and must be filed even if you have already submitted your federal return to the Internal Revenue Service.

2. Who Must File Delaware State Income Tax?

You may need to file a Delaware state income tax return if you are a Delaware resident, part-year resident, or nonresident who earned income from Delaware sources. Your filing requirement depends on factors such as residency, taxable income, and the type of income you received.

Quick checklist (common scenarios)

1. Delaware residents: May need to file based on Delaware's applicable income and filing requirements.
2. Part-year residents: Generally report income according to the period they were Delaware residents and applicable Delaware-source income.
3. Nonresidents: May need to file when they have taxable Delaware-source income.
4. Self-employed individuals: May need to report income earned from business or freelance activities connected to Delaware.
5. LLC members and sole proprietors: May have Delaware filing obligations depending on their income, residency, and business structure.

3. Which Delaware Tax Forms Do You Need?

Delaware does not use one tax form for every taxpayer. The form you need depends primarily on your residency status, income, and filing situation. For example, Delaware provides Form PIT-RES for individual resident returns and Form PIT-NON for individual nonresident returns.

Key idea

1. Delaware resident: Generally uses Form PIT-RES for an individual resident return.
2. Delaware nonresident: Generally uses Form PIT-NON for an individual nonresident return.
3. Part-year resident: Uses the appropriate Delaware return and schedules based on residency and income circumstances.
4. Self-employed taxpayer: May need additional schedules or forms depending on business and income sources.
5. Additional forms: Delaware provides separate schedules, estimated-tax forms, and other forms for specific tax situations.

Confirming your residency status and income source early helps ensure accurate Delaware state income tax filing and reduces the risk of notices from the Delaware Division of Revenue.

4. Documents Required for Delaware State Tax Filing

Preparing your documents before filing can make Delaware state tax filing easier and help reduce errors or delays. Keep your income records, tax forms, deduction information, and other documents relevant to your return available when preparing your filing.

1. W-2 and 1099 forms: Documents showing wages, contractor income, and other reported earnings.
2. Federal tax return: Useful for information that carries into the Delaware return.
3. Delaware withholding records: Records showing Delaware income tax withheld during the year.
4. Business income records: Income and expense information for self-employed taxpayers or business owners.
5. Prior-year Delaware return: Helpful for checking previous information and carryforward items. 

5. DIY vs Accountant vs Managed Filing

Taxpayers and business owners generally have three options for handling their Delaware tax filing: file themselves, work with an accountant, or use a managed filing service. The right option depends on the complexity of the return, available time, and level of support needed.

What typically changes your complexity?

1. Multiple LLCs or multiple partners
2. US-source income / withholding / treaty-related details
3. High bank activity and many transactions

Why founders choose managed filing

1. Fewer missed filing requirements
2. Clear checklist and filing timeline
3. Help selecting the appropriate forms
4. Less administrative back-and-forth

6. Step-by-Step: How to File Delaware State Income Tax

Step 1: Confirm your Delaware residency status

Start by determining whether you are a Delaware resident, part-year resident, or nonresident. Residency status determines whether you file Form 40, Form 40A, or Form 40NR for Delaware State Tax Filing.

Step 2: Gather income records and federal return details

Collect W-2s, 1099s, and your federal income tax return. Delaware state income tax filing uses federal income figures as the starting point for calculating state tax.

Step 3: Review Delaware-specific deductions and withholding

Verify Delaware tax withheld and applicable deductions, including the Delaware deduction for federal income tax paid. Accurate withholding information helps prevent balances due or delayed refunds.

Common filing deadline: April 15 for most calendar-year filers

Step 4: Prepare and review the Delaware tax return

Complete the appropriate Delaware tax form using the My Delaware Taxes (Delaware’s official tax portal) portal, approved tax software, or professional assistance. Review entries carefully before submission.

Step 5: Submit the return and retain confirmation

File your return electronically or by mail and keep a copy of the filed return, payment confirmation, or refund notice for your records.

Step 6: Plan for next tax year

Maintain organized income and expense records throughout the year to simplify future Delaware State Tax Filing and reduce the risk of errors.

Helpful IRS reference:

• IRS Small Business and Self-Employed resources
• Employer Identification Number information

If you prefer guided assistance, FormLLC can help confirm your Delaware filing requirements and coordinate the preparation process.

7. Tips to Avoid Delaware Tax Notices and Penalties

• File your Delaware income tax return by the applicable deadline Pay any tax due on time, even if you request an extension to file
• Review your Delaware withholding and income information before submitting
• Keep copies of your filed return, payment records, and supporting documents
• Respond promptly to notices from the Delaware Division of Revenue

8. Delaware Tax Costs, Penalties, and Filing Deadlines

• Tax preparation cost: Varies depending on the complexity of your return and whether you file yourself or use professional assistance

• Record preparation: Organizing income, withholding, and supporting documents can help reduce filing errors 
• Late-filing penalty: A balance-due Delaware income tax return can be subject to a 5% penalty per month of the balance due
• Interest on unpaid tax: Interest on underpaid or late-paid Delaware income tax accrues at 0.5% per month
• Failure-to-pay penalty: An additional 1% per month, up to 25%, may apply when tax due is not paid on time

9. Common Federal and Delaware Tax Forms

1. EIN (Employer Identification Number)

An Employer Identification Number (EIN) is issued by the Internal Revenue Service and is used to identify a business for federal and state tax reporting, including Delaware state income tax filing for businesses and self-employed individuals.

2. Federal Partnership Return (Form 1065)

Multi-member LLCs file a federal informational return using Form 1065 . Income reported on Schedule K-1 is used to complete Delaware state income tax returns for individual partners.

3. Federal Corporate Return (Form 1120)

US C-Corporations file Form 1120 at the federal level. Corporate income figures are used to determine Delaware tax obligations when applicable.

4. Delaware Individual Income Tax Forms

• Form 40: Delaware resident individual income tax return.
• Form 40A: Short form for Delaware residents with simple tax situations.
• Form 40NR: Required for nonresidents and part-year residents with Delaware-source income.

5. Owner Individual Filing (when applicable)

• Individuals report Delaware income using Form 40, 40A, or 40NR based on residency
• Partners use Schedule K-1 information to complete Delaware individual returns
• Federal ITIN or SSN may be required for individual Delaware tax filing

10. Conclusion

Delaware state income tax filing is an important annual responsibility for taxpayers who are required to file a Delaware return. Filing accurately, paying any tax due on time, and keeping proper records can help reduce the risk of penalties, interest, and compliance issues.

By understanding Delaware tax filing requirements, forms, deadlines, and payment rules, taxpayers can prepare their state returns more efficiently. FormLLC can help business owners understand the filing process and stay organized with their Delaware compliance requirements.