Louisiana State Income Tax Filing Guide

1. What Is Louisiana State Tax Filing?

Louisiana state income tax filing refers to the process of reporting certain types of income to the Louisiana Department of Revenue. Importantly, Louisiana imposes a personal state income tax on individuals, while businesses may be subject to separate corporate or industry-specific taxes.

However, specific filing obligations still exist for nonresidents with Louisiana-source income, certain pass-through entities, fisheries businesses, mining license tax, oil & gas-related activities, and other special taxes. This is separate from federal income tax filing with the IRS.

2. Who Must File in Louisiana?

Most individuals who meet income thresholds or have Louisiana-source income must file a Louisiana state income tax return. However, filing may still be required in these situations:

Quick checklist (common scenarios)

1. Nonresidents with Louisiana-source income (wages, business, rental, royalties, fisheries, etc.)
2. Part-year residents must file for the portion of the year they lived or earned income in Louisiana
3. Individuals or entities subject to fisheries business tax, mining license tax, or oil & gas production / property tax
4. Pass-through entities (partnerships, S corps, LLCs) that must file informational returns
5. Taxpayers who had Louisiana tax withheld and want to claim a refund

3. Louisiana Tax Forms – What to File

Louisiana does require individuals to file a personal state income tax return if they meet income thresholds or have Louisiana-source income. Standard Louisiana individual income tax forms apply to most resident, part-year resident, and nonresident taxpayers.

When Louisiana tax forms are required

1. Individual income tax returns (Form IT-540 or IT-540NR) are required for residents, part-year residents, and nonresidents with Louisiana-source income
2. Corporate Net Income Tax returns apply to C-Corporations doing business in Louisiana
3. Fisheries Business Tax filings apply to qualifying fishing-related activities
4. Mining License Tax filings apply to mining operations
5. Oil & Gas Production and Property Tax filings apply to energy-sector businesses

Individuals living in or earning income from Louisiana are generally subject to Louisiana state income tax. Identifying the correct forms early helps ensure accurate filing and compliance.

4. Documents Required for Louisiana Tax Filing

If you are required to file a Louisiana state tax return, prepare the following documents in advance:

1. W-2 and 1099 forms: showing wages or other income earned in Louisiana
2. Federal tax return (Form 1040): used as the starting point for Louisiana calculations
3. Louisiana withholding records: showing any Louisiana state income tax withheld
4. Business, rental, or industry income records: income, expenses, and supporting documentation
5. Prior Louisiana tax returns (if any): for reference, consistency, and carryforwards

5. DIY vs Accountant vs Managed Filing

Non-US founders and remote business owners with Louisiana filing obligations typically choose one of three approaches: DIY filing, hiring an accountant, or using managed tax filing services.

What typically increases complexity?

1. Louisiana-source income (wages, business income, rentals, fisheries, mining, oil & gas)
2. Multi-state operations and income apportionment requirements
3. Pass-through entities with Louisiana nexus or reporting obligations

6. Step-by-Step: Louisiana State Tax Filing

Step 1: Confirm your Louisiana filing requirement

First, determine whether you are classified as a Louisiana resident, part-year resident, or nonresident. Louisiana state income tax filing is generally required if you meet income thresholds or earn Louisiana-source income.

Step 2: Ensure you have the correct tax identification numbers

Before filing, confirm that you have the appropriate identification:

• Social Security Number (SSN) or ITIN for individuals
• Employer Identification Number (EIN) for businesses, partnerships, or LLCs with Louisiana tax obligations

If you do not yet have an EIN, you can apply directly with the IRS: Apply for an EIN on the IRS website .

Step 3: Gather federal and Louisiana income documents

Louisiana state returns are closely tied to your federal tax filing. Collect the following before preparing your return:

• Federal income tax return (Form 1040)
• W-2 and 1099 forms showing Louisiana-source income
• Business income and expense records (Schedule C, E, or K-1 if applicable)
• Louisiana state tax withholding statements

Federal forms and instructions are available directly from the IRS: IRS Forms & Instructions .

Step 4: Select the correct Louisiana tax form

Choose the appropriate Louisiana return based on your residency status:

• Form IT-540 – Louisiana Resident Individual Income Tax Return
• Form IT-540NR – Nonresident and Part-Year Resident Income Tax Return

Step 5: Prepare and submit the return

Louisiana returns may be filed electronically through approved tax software or by using the Louisiana Department of Revenue’s online services. Review all income, deductions, and credits carefully before submission.

Standard filing deadline: May 15 for most calendar-year filers. Extensions may be available, but any tax owed must be paid by the original deadline.

Step 6: Retain records and plan ahead

After filing, keep copies of your Louisiana return, proof of payment, and supporting documents for your records. Maintaining organized income and withholding records throughout the year helps reduce errors and simplifies future Louisiana and federal filings.

7. Tips to Avoid Louisiana Tax Notices

• Confirm whether you are required to file based on residency status and income thresholds
• Report all Louisiana-source income accurately
• File by the Louisiana filing deadline (generally May 15 for individuals)
• Keep clear records of income sources, deductions, and apportionment
• Respond promptly to any correspondence from the Louisiana Department of Revenue

8. Louisiana Tax Costs, Penalties, and Filing Timelines

• Personal income tax rate: Progressive rates based on taxable income
• Late filing penalty: 5% of tax due per 30-day period, up to a maximum of 25%
• Interest on unpaid tax: Accrues at rates set annually by the Louisiana Department of Revenue
• Filing extensions: Automatic extension to November 15 if a federal extension is filed; payment is still due by the original filing deadline

9. Common Federal & Louisiana Tax Forms

Federal Tax Forms (Commonly Used)

• Form 1040 – U.S. Individual Income Tax Return
• Schedule C – Profit or Loss From Business (sole proprietors)
• Schedule E – Supplemental Income (rentals, royalties, pass-through income)
• Schedule K-1 – Partnership or S-Corporation income reporting

Louisiana Tax Forms

• Form IT-540 – Louisiana Resident Individual Income Tax Return
• Form IT-540NR – Nonresident and Part-Year Resident Income Tax Return
• Louisiana Corporate Income Tax Return – For C-Corporations with Louisiana nexus
• Fisheries Business Tax filings administered by the Louisiana Department of Revenue
• Mining License Tax filings based on Louisiana mining income
• Oil & Gas–related tax and production filings for applicable energy-sector activities

10. Conclusion

Louisiana imposes a personal state income tax on residents, part-year residents, and nonresidents with Louisiana-source income. While tax rates and filing rules vary by situation, understanding your residency status and income sources is key to staying compliant.

Taking the time to confirm your filing requirements helps you avoid penalties, delays, and unnecessary issues. FormLLC can help review your Louisiana tax obligations and guide you through the filing process clearly and efficiently.