Modifies statutory timelines, penalty calculations, and exceptions for penalties for the payment of certain estimated taxes (RE INCREASE SG RV See Note)

House Bill 633 amends the Louisiana estimated income tax statutes by modifying filing deadlines, adjusting penalty calculation periods, and eliminating certain penalty exemption calculations. The bill changes multiple references in the Revised Statutes from the 15th day of the fourth month to the 15th day of the fifth month following the close of the taxable year in several contexts: the period during which the underpayment penalty runs for both individual and corporate taxpayers, the deadline for corporate assessments of excessive adjustment penalties, and the deadline for corporations to file applications for adjustment of estimated tax overpayments. Additionally, the bill repeals the annualized income calculation method that previously allowed individual taxpayers to avoid estimated tax penalties by demonstrating that their estimated tax payments equaled or exceeded ninety percent of tax computed on an annualized basis, while retaining the eighty percent safe harbor for corporate taxpayers but removing the annualized computation alternative for corporate filers as well.

The practical effect of these changes impacts individual income taxpayers and corporations making estimated tax payments to Louisiana. Individual taxpayers will lose an alternative penalty exemption pathway that previously allowed them to avoid penalties through annualized income calculations, meaning they must now rely on other available exemptions or ensure full payment. Corporations will similarly lose the annualized computation method for penalty exemption while maintaining the ability to avoid penalties by paying at least eighty percent of the current year tax, thereby narrowing their exemption options. The extension of filing deadlines from the fourth month to the fifth month provides taxpayers an additional month to remit estimated tax payments, file adjustment applications, or settle underpayment obligations before the penalty accrual period concludes. The Treasury Department's penalty calculation and assessment procedures will operate on the extended timeline, affecting the administrative processing of estimated tax matters and penalty determinations.

House Bill 633 operates within Louisiana's income tax framework established in the Revised Statutes Title 47. The legislation specifically modifies provisions governing individual estimated income tax penalties under Section 118 and corporate estimated income tax penalties under Sections 287.655 and 287.656. These statutes establish the legal obligation for taxpayers to make quarterly estimated tax payments and impose administrative penalties for underpayment or excessive adjustments. By extending the deadline and eliminating certain exemption calculations, the bill maintains the penalty structure while adjusting the timeline for penalty accrual and the available affirmative defenses against such penalties. The changes apply prospectively to taxable periods beginning on or after January 1, 2026, ensuring taxpayers have notice before the statutory modifications take effect.