How to File Your Louisiana Tax Return: Guide to Tax Year 2018

In 2018, Louisiana taxpayers who filed their returns electronically often received refunds in as little as 45 days, while those who relied on paper filing waited up to 14 weeks. That gap can be the difference between having funds available to cover bills, pay down debt, or invest sooner rather than later. Choosing the correct filing method can have a tangible impact on your timing and finances.

Filing your Louisiana tax return for 2018 is more than a yearly obligation. It’s an opportunity to secure your refund quickly, avoid penalties, and ensure every eligible deduction or credit works in your favor. Whether you are a full-year resident, a nonresident with Louisiana-sourced income, or a small business owner, understanding the process from start to finish will help you prevent costly mistakes. The Louisiana Department of Revenue sets precise requirements, and following them closely can keep your return from being delayed or rejected.

This guide will walk you through how to file your Louisiana tax return. You’ll learn who must file, which forms are required, and how to complete your return accurately. We’ll also cover payment options, how to track your refund, and the errors that cause the most delays. Each section combines official filing requirements with practical tips to file confidently. Whether meeting the original deadline or catching up after missing it, the goal is to help you save time, reduce penalties, and avoid unnecessary stress.

Who Needs to File a Louisiana Tax Return for 2018

Louisiana’s filing requirements for 2018 depend on your residency status, income level, and whether you are subject to federal filing requirements. For most taxpayers, if you were required to file a federal return for 2018, you must also file a Louisiana return.

Full-Year Residents

If you lived in Louisiana for the entire year, you must file a state return if:

You were required to file a federal individual income tax return for 2018.
Your income exceeded the federal filing threshold for your filing status.
Louisiana income tax was withheld from your wages, and you want to claim a refund.

The state uses a three-bracket tax system for 2018:

2% on taxable income up to $12,500 for single filers ($25,000 for married filing jointly)
4% on the next $37,500 for single filers ($75,000 for married filing jointly)
6% on income above those levels

Part-Year Residents

If you moved into or out of Louisiana during 2018, you are considered a part-year resident. You must file Form IT-540B to report Louisiana income earned while living in the state. This includes wages, rental, or business income earned during residency.

Nonresidents

If you did not live in Louisiana but earned income from Louisiana sources in 2018, you must also file Form IT-540B. This includes wages from Louisiana employers, rental income from Louisiana property, or business income tied to Louisiana operations. Only income sourced to Louisiana is subject to the Louisiana state tax.

Special Circumstances

Professional Athletes: Must file a specialized nonresident return electronically.
Refund-Only Filers: Even if you were not required to file based on income, you should file if you had Louisiana tax withheld or made estimated tax payments and want a refund.
Underpayment Penalties: If you did not pay enough throughout the year via withholding or estimated payments, you may be subject to penalties and should file to settle your total tax owed.

Knowing whether you must file is the first step to avoiding penalties and ensuring your refund is processed immediately. Filing even when not strictly required can prevent issues with unclaimed credits, overpaid taxes, and account discrepancies with the Louisiana Department of Revenue.

Key Dates and Deadlines

For the 2018 tax year, Louisiana set precise filing dates to help taxpayers avoid penalties and interest charges. Missing these deadlines can result in additional costs that quickly add up.

Original Due Date

Your Louisiana individual income tax return for 2018 was due May 15, 2019. This date applies to residents and nonresidents filing Form IT-540 or Form IT-540B. Filing on or before this date helps you avoid the 10% late filing penalty and ensures your refund is processed sooner.

Extension Due Date

If you submitted an Application for Extension of Time to File (Form R-2868) by the original due date, you had until November 15, 2019, to file your return. Remember that an extension applies only to the filing deadline, not the payment deadline. Any total tax owed still had to be paid by May 15 to avoid a 5% late payment penalty per month plus interest.

Estimated Tax Payments

If you expected to owe at least $1,000 in total tax for 2018, you were generally required to make estimated tax payments. These were due quarterly: April 15, June 15, September 1, 2018, and January 15, 2019. Failure to make sufficient estimated payments can result in an underpayment penalty. Marking these dates in your calendar and submitting your return early prevents penalties and gives you a buffer in case of rejected returns or processing delays.

Forms and Documents You Need

Filing your 2018 Louisiana tax return requires the correct forms and supporting documents. Using the wrong form year or missing required attachments can cause your return to be rejected or delayed during processing.

Primary Forms

Form IT-540: Louisiana Resident Individual Income Tax Return, for full-year residents.
Form IT-540B: Nonresident and Part-Year Resident Individual Income Tax Return.
Form IT-540ES: Estimated Tax Voucher, used to make quarterly estimated tax payments.
Form R-2868: Application for Extension of Time to File, submitted before the original due date.
Special Nonresident Forms: Certain individuals, such as professional athletes, have specific filing requirements and must file electronically.

Schedules and Worksheets

Depending on your situation, you may need to attach:

Credit schedules for nonrefundable and refundable credits.
The Consumer Use Tax Worksheet for out-of-state purchases.
Worksheets for the School Readiness Credit or Child Care Credit, if applicable.

Supporting Documents

Gather all paperwork before starting your return to ensure accurate entries:

Income Statements: W-2 forms from employers and 1099 forms for interest, dividends, or miscellaneous income.
Federal Return: A copy of your federal Form 1040 for 2018, as Louisiana income calculations often begin with your federal adjusted gross income.
Proof of Payments: Records of estimated tax payments, account transactions, and any prior-year overpayments applied to 2018.
Deduction and Credit Records: Receipts for charitable contributions, mortgage interest statements, and state/local tax payment records.

Official Form Source

Always download forms directly from the Louisiana Department of Revenue website. This ensures you have the correct version with the official Louisiana state seal and avoids outdated or altered forms that could be rejected. Having all necessary forms and documents before you begin will save time, reduce errors, and help you complete your return accurately the first time.

Step-by-Step Guide to Completing Your Louisiana Tax Return

Filing your Louisiana tax return for 2018 requires a methodical approach to ensure accuracy, avoid penalties, and speed up processing. Below is a nine-step process that will help you complete your return correctly the first time.

Step 1: Gather All Required Documents

Before you start, assemble everything you need:

Your 2018 federal tax return (Form 1040).
All W-2 forms from employers.
All 1099 forms for interest, dividends, or miscellaneous income.
Records of estimated tax payments made during 2018.
Receipts for deductible expenses such as charitable contributions and mortgage interest.

Having this information ready will save time and prevent missing entries that could lead to a rejected return or delayed refund.

Step 2: Determine Your Filing Status

Use the same filing status on your Louisiana return as on your federal return:

Single
Married Filing Jointly
Married Filing Separately
Head of Household
Qualifying Widow(er)

Choosing the correct status impacts your standard deduction, exemptions, and total tax calculation.

Step 3: Enter Your Personal Information

On Form IT-540 or IT-540B:

Enter your legal name exactly as shown on your Social Security card.
Provide your current address and daytime phone number.
Include Social Security numbers and dates of birth for yourself and your spouse.
Mark boxes for any name or address changes since last year.

Accurate information ensures your return is matched to the correct account and processed without errors.

Step 4: Calculate Your Louisiana Income

Residents (Form IT-540):

Start with your Federal Adjusted Gross Income.
Add any Louisiana-specific additions (for example, certain federal exemptions not recognized by Louisiana).
Subtract allowable Louisiana-specific deductions, such as Social Security benefits, which are not taxable in the state.

Nonresidents and Part-Year Residents (Form IT-540B):

Complete the Nonresident and Part-Year Resident (NPR) Worksheet to determine Louisiana-sourced income.
Only income earned in or derived from Louisiana is subject to the Louisiana state tax.
Calculate the ratio of Louisiana income to total federal revenue. This ratio will be used to determine your Louisiana tax liability.

Step 5: Claim Your Deductions

You can either take the Louisiana standard deduction or itemize deductions:

Standard Deduction: Automatically applied based on filing status.
Itemized Deductions: If you itemized on your federal return, you may also itemize on your Louisiana return.

Federal Income Tax Deduction

Louisiana allows you to deduct federal income tax paid during the year. This includes Net Investment Income Tax from federal Form 8960. Use the Federal Income Tax Deduction Worksheet to calculate this amount.

Step 6: Calculate Your Total Tax

Use the Louisiana tax tables or the computation worksheet included with your form.

Apply the correct tax rates (2%, 4%, 6%) to your taxable income.
Deduct personal exemptions and dependent credits.
For nonresidents, multiply the tax amount by your Louisiana income ratio from Step 4.

Step 7: Apply Credits

Nonrefundable Credits (reduce tax owed but do not create a refund):

Carry forward child care credits from prior years.
School readiness credits carry forward.
Particular investment or business-related credits.

Refundable Credits (can create a refund even if you owe no tax):

Child care credit for taxpayers with a federal AGI of $25,000 or less.
School readiness credit for qualifying expenses.
Citizens Property Insurance assessment credit.

Attach the required schedules and proof for each credit to avoid processing delays.

Step 8: Report Consumer Use Tax

If you purchased goods from out-of-state sellers and did not pay Louisiana sales tax, you must report consumer use tax:

9% for purchases before July 1, 2018.
8.45% for purchases on or after July 1, 2018.

Include online purchases, catalog orders, and out-of-state store purchases where sales tax was not collected.

Step 9: Review Before Submitting

Before filing, check:

All math calculations.
Correct form year (2018 only).
Required W-2s, 1099s, and supporting schedules are attached.
Signatures and dates are included (both spouses if filing jointly).

Submitting a complete and accurate return the first time will help avoid processing delays and underpayment notices. Following these steps will help you complete your Louisiana tax return accurately and on time, reducing the risk of penalties and ensuring that any refund you are owed is processed as quickly as possible.

Filing Methods: E-File vs. Paper

Choosing how you file your Louisiana tax return for 2018 can directly affect how quickly it is processed and when you receive your refund. The Louisiana Department of Revenue offers electronic and paper filing, but the differences in speed and convenience are significant.

Electronic Filing (E-File)

E-filing is the preferred method for most taxpayers because it offers:

Faster Processing: Refunds from e-filed returns can be received in as little as 45 days compared to 14 weeks for paper returns.
Immediate Confirmation: You receive instant notification that your return has been received.
Built-In Error Checking: The system flags common mistakes before submission, reducing the risk of a rejected return.
Direct Deposit: Refunds can be deposited directly into your bank account, avoiding mail delays.

You can e-file through the Louisiana Department of Revenue’s online filing service or by using approved commercial tax preparation software. Professional preparers can also submit your return electronically on your behalf.

Paper Filing

Paper filing is slower and requires mailing your completed return to the correct address:

With Payment:
Louisiana Department of Revenue

P.O. Box 3550

Baton Rouge, LA 70821-3550

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Without Payment (refund or zero balance):
Louisiana Department of Revenue

P.O. Box 3440

Baton Rouge, LA 70821-3440

Paper Filing Tips:

Use black ink and print clearly.
Do not fold or staple forms.
Keep copies of everything you mail.

While paper filing is still an option, the slower processing time makes e-filing the most efficient choice for most individuals, especially if you want your refund quickly or need confirmation that your return was received.

Payment Options and Plans

If you owe total tax when filing your Louisiana tax return 2018, the Louisiana Department of Revenue offers several ways to pay. Choosing the correct method can help you avoid penalties, interest, and delays in processing your return.

Online Payments via LaTAP

The Louisiana Taxpayer Access Point (LaTAP) is the fastest payment method. Available at latap.revenue.louisiana.gov, it allows you to:

Pay directly from your bank account via ACH debit (no fee).
Use a credit card (a convenience fee applies).
Pay by electronic check.
View your account balance, payment history, and any penalties assessed.

Payments made through LaTAP are usually posted to your account quickly, helping you meet your due date and avoid late payment charges.

Pay by Mail

If you prefer to pay by mail:

Make your check or money order payable to “Louisiana Department of Revenue.”
Write the last four digits of your Social Security number and the tax year (2018) on the payment.
Attach the payment to your return and mail it to the appropriate address listed for returns with payment.
Never send cash.

Requesting a Payment Plan

If you cannot pay the full amount immediately, you may apply for a payment plan through LaTAP. This allows you to spread payments over time while avoiding more serious collection actions. However, interest will continue to accrue on the unpaid balance.

Penalties for Late Payment

Failing to pay by the original due date can result in a 5% late payment penalty per month, up to a maximum of 25%, plus interest. Even if you cannot pay in full, submitting your return on time can help you avoid the higher 10% late filing penalty.

Paying your tax in full, on time, and using a secure method is the best way to protect your account, reduce penalties, and keep your record in good standing with the Louisiana Department of Revenue.

How to Track Your Refund

Once you have submitted your Louisiana tax return for 2018, the next step for many taxpayers is checking the status of their refund. The Louisiana Department of Revenue offers convenient online tools to make this process quick and accessible.

Where’s My Refund?

The “Where’s My Refund?” feature on the Department’s website allows you to:

View the current status of your refund.
See if your return has been processed.
Confirm when your payment has been approved for mailing or direct deposit.

You will need your Social Security number, filing status, and the exact refund amount to use this service.

Processing Periods

E-filed returns are typically processed within 45 days, while paper-filed returns can take up to 14 weeks. These timeframes can extend if there are errors, missing documents, or security reviews. Filing before the original due date helps ensure your refund enters processing sooner.

Reasons for Delays

Your refund may be delayed if:

Your return is selected for review to verify income or deductions.
There are discrepancies between your Louisiana return and your federal IRS return.
You have unpaid state obligations, such as prior-year tax or penalty balances, which can be offset against your refund.

How to Check Your Account

Through the Louisiana Taxpayer Access Point (LaTAP), you can view your account, see the date payments or refunds were issued, and confirm whether any adjustments were made. Track your rebate at regular intervals rather than checking daily. Processing takes time, and the online system updates as your return moves through each step.

Common Mistakes to Avoid

Even a small error on your Louisiana tax return for 2018 can slow down processing or trigger a review. Avoiding these issues will help you receive your refund faster and reduce the risk of additional charges.

Missing the Due Date: Filing after the original due date can result in a 10% late filing penalty and interest charges on any unpaid total tax. If you cannot pay in full, submit your return on time to avoid the higher penalty.
Mathematical Errors: Simple math mistakes are among the most common causes of delays. To prevent these errors, use e-filing services with built-in calculations.
Omitting Required Documentation: Forgetting to attach W-2s, 1099s, or credit schedules can lead to your return being rejected. Always double-check your supporting documents before submitting.
Using the Wrong Form Year: Ensure you are filing the correct 2018 forms. Using the wrong year’s form will result in processing delays and could require resubmission.
Mismatch Between Federal and State Returns: The Louisiana Department of Revenue often compares state returns with information from the IRS. Expect a review and possible delay if your federal and state returns have inconsistent data.
Not Reviewing Before Submitting: A quick review can catch errors with Social Security numbers, filing status, or income entries. These are common reasons for rejected returns.
Failing to Report Consumer Use Tax: If you made purchases without paying Louisiana sales tax, you must report and pay the applicable consumer use tax to avoid an underpayment penalty.

By reviewing your return, matching it to your federal IRS records, and meeting the filing deadline, you can avoid unnecessary delays and costly penalties.

Final Filing Checklist

Before submitting your 2018 Louisiana tax return, use this checklist to ensure your return is complete and ready for processing. A thorough review now can prevent delays, rejections, and penalties later.

Forms and Documents

Completed and signed Form IT-540 or Form IT-540B for 2018.
All W-2 forms and any 1099s that show Louisiana tax withheld.
Required schedules for credits, deductions, or consumer use tax.
Federal Form 1040 for reference and comparison.

Payment and Refund Information

The payment method is selected if you owe total tax.
Check or money order made payable to the Louisiana Department of Revenue if paying by mail.
The bank account and routing numbers were entered correctly for direct deposit refunds.

Review and Accuracy

Confirm filing status matches your federal return.
Verify all Social Security numbers and dates of birth.
Ensure income and deductions are entered accurately.
Check calculations or use e-file to avoid math errors.

Mailing or Submission

Use the correct mailing address for returns with or without payment for paper filing.
Keep copies of your return and all supporting documents for at least four years.

Completing this checklist will help ensure that your return is accurate, timely, and ready for smooth processing by the Louisiana Department of Revenue.

Frequently Asked Questions (FAQs)

What if I missed the due date for my 2018 Louisiana tax return?

If you missed the original due date, file as soon as possible to reduce the late filing penalty, which is generally 10% of the tax owed, plus interest. Submitting quickly can minimize charges and get your return processed sooner. Even if you cannot pay in full, filing promptly avoids the higher penalty for failing to file.

How can I request a payment plan if I cannot pay in full?

The Louisiana Department of Revenue allows taxpayers to request a payment plan through the Louisiana Taxpayer Access Point (LaTAP). This lets you make smaller, regular payments over a set period. While interest will continue to accrue, a payment plan can prevent more serious collection actions and keep your account in good standing.

Where can I find the correct form and instructions for my 2018 Louisiana return?

You can download the official form and instructions for your 2018 Louisiana tax return from the Louisiana Department of Revenue’s tax forms page. Using the correct year’s form ensures proper processing and prevents rejection. Always confirm the form shows the official Louisiana state seal to verify authenticity and accuracy before completing and submitting your return.

How do I use the refund status page to check my return?

The refund status page on the Louisiana Department of Revenue’s website lets you view the current stage of your return’s processing. You will need your Social Security number, filing status, and exact refund amount. The system updates regularly, so checking once a week is usually enough to track your progress without unnecessary repeated logins.