Does Montana Have a Sales Tax? Penalties & What Applies

Estimate Your Montana Tax Balance

Montana does not have a sales tax balance to calculate in the traditional sense. If you owe lodging tax, resort tax, or another specific-use tax, the penalty and interest due depend on the type of tax, how long it has been outstanding, and whether a return was filed. The Department of Revenue administers the state lodging tax through the TransAction Portal (TAP). Resort taxes are administered locally by each resort community, not by the Department of Revenue.

If you have received a notice from either the Department of Revenue or a local resort community, the figures below can help you understand what categories of charges may be building up on the unpaid tax.

How Montana Tax Penalties and Interest Work

Montana's penalty and interest system is governed by MCA §15-1-216, which establishes uniform penalty and interest assessments for violations of tax provisions across most taxes administered under Title 15. The statute covers lodging taxes, rental vehicle taxes, and income-based taxes, but does not apply to property taxes or gasoline and vehicle fuel taxes collected by the Department of Transportation.

The late filing penalty is the greater of $50 or 5% of the tax due for each month or fraction of a month that a return is late, capped at 25% of the tax due. There is also a separate late payment penalty of 0.5% per month on the unpaid tax, up to 12%, or 1.5% per month up to 15% for certain tax types, including lodging taxes and estimated tax payments. Interest accrues daily on the unpaid tax from the original due date of the return, regardless of whether an extension was granted for filing.

Late Filing vs. Late Payment Penalties in Montana

Montana charges separate penalties for late filing and late payment, and both can apply to the same period.

The late filing penalty is the greater of $50 or 5% of the tax due for each month of delay, up to 25%. The late payment penalty is 0.5% per month on unpaid amounts, up to 12% — but for lodging facility taxes, rental vehicle taxes, estimated taxes, and certain other specific taxes under Title 15, the late payment penalty rises to 1.5% per month, up to 15% of the tax due. (MCA §15-1-216(2)(b))

Both penalties may be waived if the taxpayer pays the tax and interest due with the tax return or report within 30 days of the first notice from the Department of Revenue. A penalty may not be imposed on the amount of unpaid tax if the taxpayer demonstrates reasonable cause for the failure to pay the tax. Reasonable cause means the taxpayer exercised ordinary business care but was still unable to meet the department's deadline.

Example: If a lodging facility owed $10,000 in combined lodging taxes for a quarter, filed three months late, and paid nothing in the interim, the late filing penalty alone could reach $1,500 (5% × 3 months × $10,000), and the late payment penalty could add up to $450 more (1.5% × 3 months × $10,000), before interest is calculated.

How Montana Interest Applies

Montana charges interest on outstanding taxes and underpaid estimated taxes, computed daily beginning on the original due date of the tax return. For 2026, the Department of Revenue has set two different interest rates depending on the tax type.

For individual income tax, estate and trust taxes, and pass-through entity taxes, the 2026 annual interest rate is 7%, computed daily at 0.019178%. For all other taxes — including lodging facility taxes, rental vehicle taxes, and telecommunications taxes — the 2026 interest rate is 10.25% per year, computed daily at 0.028082%.

Interest accrues daily on the unpaid tax from the original due date. Under MCA §15-1-216(9), any changes to interest rates apply to any current outstanding tax balance, regardless of the rate in effect at the time the tax accrued. This means interest due on a balance from a prior year recalculates at the current rate going forward. The provision for interest on overpayments is narrower: the interest allowed for the overpayment of taxes uses the subsection (7)(a)(i) rate, rather than each tax type's delinquent rate. (MCA §15-1-216(12))

Interest Rate

Montana's 2026 interest rates, per the Department of Revenue:

• Individual income tax, estate and trust, pass-through entities: 7% annually (0.019178% daily)
• All other taxes (including lodging): 10.25% annually (0.028082% daily)

For all other taxes, the interest rate is equal to 3 percentage points above the prime rate published by the Federal Reserve System in its statistical release H.15 for bank prime loans for the last business day of the third quarter of the preceding year. (MCA §15-1-216(7)(a)(ii)(B)) For individual income taxes, the interest rate is determined in subsection (7)(a)(i) of MCA §15-1-216, tied to the federal underpayment rate under 26 U.S.C. §6621 for the third quarter of the preceding year. Changes to interest rates apply to any current outstanding tax balance prospectively.

Historical interest rates on delinquent taxes administered by the department:

• 2020 — Individual Income Tax: 5.00% | All Other Taxes: 8.00% 
• 2021 — Individual Income Tax: 3.00% | All Other Taxes: 6.25% 
• 2022 — Individual Income Tax: 3.00% | All Other Taxes: 6.25% 
• 2023 — Individual Income Tax: 5.00% | All Other Taxes: 9.25% 
• 2024 — Individual Income Tax: 7.00% | All Other Taxes: 11.50% 
• 2025 — Individual Income Tax: 8.00% | All Other Taxes: 11.00% 
• 2026 — Individual Income Tax: 7.00% | All Other Taxes: 10.25%

Why Montana's Tax Structure Is Different

Unlike states with a statewide sales tax, Montana raises revenue through income taxes, property taxes, and targeted transaction taxes. For most businesses, there is no tax return to file for retail sales, and no sales tax registration is required. The absence of a general sales tax is intentional and longstanding — Montana is one of five states that has never imposed one.

That said, several taxes do apply to specific industries and transactions, and failing to pay the tax when due in those categories carries real consequences. The tax liability for lodging operators and rental vehicle companies is enforceable by the Department of Revenue, while taxes in resort communities are enforced locally by community governments under local rules. The department may file warrants and liens, issue levies against business bank accounts, and pursue responsible persons personally for collected but unremitted taxes under the state's responsible-party collection rules.

Tax Penalties in Montana That Do Apply

Even without a general sales tax, several Montana tax types carry penalties and interest exposure.

• Lodging Facility Sales and Use Tax: Montana imposes a combined 8% lodging facility sales and use tax on overnight accommodations — a 4% lodging facility use tax under MCA Title 15, chapter 65, plus a 4% lodging sales tax under MCA Title 15, chapter 68. This tax applies to hotels, motels, short-term rentals, campgrounds, bed and breakfasts, and similar lodging for periods under 30 consecutive days. Operators must register with the Department of Revenue, collect the tax from guests, and file a return on a quarterly basis. The late payment penalty for lodging taxes is the higher rate of 1.5% per month on the unpaid tax, up to 15%.
• Rental Vehicle Tax: Montana imposes a rental vehicle tax on short-term vehicle rentals. The same higher penalty structure applies: 1.5% per month on the unpaid tax, up to 15%, plus daily accruing interest at the applicable rate.
• Resort Taxes: Certain Montana communities — including Big Sky, West Yellowstone, Whitefish, Red Lodge, and Virginia City — are authorized to impose a local resort tax of up to 4% on the retail value of certain goods and services sold within their boundaries. These are administered locally by each community, not by the Montana Department of Revenue. Failure to register or remit may still result in penalties, unpaid tax liability, and interest under local enforcement rules.
• Individual Income Tax: Montana's individual income tax applies to residents and certain nonresidents on Montana-source income, with graduated rates from 4.7% to 5.65% for 2026. Failure to file or pay the tax on time triggers the same penalty structure under MCA §15-1-216, with interest accruing at 7% for 2026.

Additional Montana Tax Penalties

Montana's uniform penalty framework includes several additional penalties beyond late filing and late payment.

• Failure-to-File Penalty (Intentional): A person who purposely or knowingly fails to file a return or report, or who fails to file within 60 days of receiving written notice from the department, is liable for 15% of the tax due per month, up to 75% of the tax due. This is separate from the standard late filing penalty. The department may bring an action in the name of the state to recover the penalty and any delinquent taxes. (MCA §15-1-216(4))
• Substantial Understatement of Tax Penalty: A substantial understatement of tax penalty is imposed when a taxpayer understates their tax liability by more than 10% of the tax required to be shown on the return, with a $3,000 threshold for individuals and a $10,000 threshold for other taxpayers. The penalty equals 20% of the understatement. The understatement of tax penalty imposed under Title 15 must be reduced by the portion attributable to items where there was substantial authority for the tax treatment, or where the relevant facts affecting the tax treatment of the item were adequately disclosed, and there was a reasonable basis for the tax treatment. (MCA §15-1-216(3))
• Fraudulent Return Penalty: A person who files a fraudulent return is liable for 75% of the tax due on the underpayment of tax attributable to the fraudulent amount reported. Where the taxpayer has no tax liability and files a fraudulent credit claim, the same 75% penalty applies to the amount of the fraudulent credit. (MCA §15-1-216(5))
• Frivolous Return Penalty: Montana charges a $2,500 frivolous return penalty for returns that omit necessary information, show a substantially incorrect tax, or are based on frivolous tax positions as identified under 26 U.S.C. §6702. (MCA §15-1-216(6))

Montana Tax Agency and Enforcement

Montana's state taxes are administered by the Montana Department of Revenue. The department's Collections Services Bureau handles enforcement, including the filing of warrants and liens, levies on bank accounts, offsets against refunds, and responsible-party collection actions. Notices arrive by mail and can range from a routine balance-due statement to a deficiency assessment to a warrant filing.

For lodging taxes, the department may require a seller to post security of up to twice the average tax liability to cover taxes, interest, and penalties owed. For resort taxes, enforcement is handled by the administering resort community rather than the Department of Revenue.

Deficiency assessments are due and payable 30 days from the date of the assessment under MCA §15-1-216(11). Failing to respond promptly typically limits the options available for appeal or resolution.

Penalty Relief, Waivers, and Resolution Options

Montana offers two pathways to avoid or reduce tax penalties.

• Automatic waiver: If a taxpayer pays the entire amount of tax and interest assessed on their account within 30 days of receiving a notice from the department, the late payment penalty is automatically waived.
• Reasonable cause waiver: A taxpayer may request a waiver of penalty by submitting a written request establishing reasonable cause for the failure to file or pay the tax. Reasonable cause means the taxpayer exercised ordinary business care but was still unable to meet the deadline. The waiver request may be submitted using Form APLS101F (Request for Informal Review) or by written request mailed to the Montana Department of Revenue, PO Box 7149, Helena, MT 59604, or by email to DORObjections@mt.gov.

Interest generally cannot be waived except in limited circumstances. Payment plans may be available through the department's Collections Services Bureau for taxpayers who cannot pay the full tax balance at once.

Montana Estimated Tax Payments and Withholding

Businesses and individuals with Montana tax obligations not fully covered by withholding may be required to make estimated tax payments during the year. Underpayment of tax on estimated payments carries a late payment penalty of 1.5% per month, up to 15%, under MCA §15-1-216(2)(b). A penalty may generally be avoided if at least 90% of the current year's tax due is paid through withholding or estimated tax payments by the due date.

‍

States that DO have a sales tax