When Are Montana Property Taxes Due? A New Owner's Calendar

Two due dates are written into state law, and neither one waits for your bill to find you. Here is the seven-date tax calendar for a first year of owning in Park County, what a late half costs, and which office fixes which problem.

If you bought property in Park County this year, or you are about to, the question behind this post is a practical one: when is the money due, and what happens if the bill goes to the wrong address or the wrong person pays it? This is written for new owners, and for buyers who close between now and spring. It gives you the two statutory due dates, the tax year each payment covers, the cost of a late half, how the homestead rate behaves in the year of a sale, and a seven-date calendar you can copy into your phone today.

When are Montana property taxes due?

Montana real property taxes are due in two halves. The first half is payable by 5 p.m. on November 30, or within 30 days after the tax notice is postmarked, whichever is later. The second half is payable by 5 p.m. on May 31. Both dates come from MCA 15-16-102, and the county treasurer collects both.

The "whichever is later" clause matters more than it looks. The first-half date moves in two cases: the county mails late, or the date lands on a Saturday or a holiday. If the notice is postmarked early enough in October that the 30 days end before November 30, the date is November 30. If it is postmarked November 10, the 30 days end on December 10, and that later date applies. In 2024, Park County's bills were mailed on October 31, according to a Livingston Enterprise report dated November 1, 2024. November 30, 2024 was a Saturday, so under the statute's next-business-day rule the first half that year was payable through 5 p.m. on Monday, December 2, 2024. In 2026, November 30 is a Monday. Read the due date printed on your own notice and treat that as the answer.

That next-business-day rule is in the same statute: when a due date falls on a Saturday or a holiday, the tax may be paid without penalty or interest by 5 p.m. on the next business day. It will come up again soon. May 31, 2027 is Memorial Day, so under the statute's holiday rule the second half of the 2026 tax would be payable through 5 p.m. on Tuesday, June 1, 2027. Confirm the date on your notice or with the Park County Treasurer before you count on the extra day.

Two exceptions are worth knowing. The owner of a primary residence can apply to the county treasurer for a schedule of seven payments of about one-seventh each, due at the end of each month from November 30 through May 31, with the full amount paid by May 31, under MCA 15-16-122. The statute defines a primary residence as one owned and occupied for at least seven months of the year, so ask the treasurer how that applies in a purchase year. And a manufactured or mobile home that is taxed as personal property, not as an improvement to land, runs on a different clock: first payment by May 31 or 30 days after the notice, whichever is later, second payment by November 30 of the same year, per MCA 15-24-202.

Which tax year does each payment cover?

Both halves on one notice cover the same calendar year. The notice that arrives in fall 2026 is the bill for tax year 2026. Its first half is due around November 30, 2026, and its second half is due around May 31, 2027, five months after the year it pays for has ended.

That lag is the source of most first-year confusion, and it shows up at closing. Under MCA 15-16-403, every tax due on real property is a lien against that property, and the lien attaches as of January 1 each year. Unpaid tax stays with the land as a lien, and the purchase agreement and the settlement statement decide how buyer and seller share the cost.

In practice that produces three situations:

1. You close between January 1 and May 31. The prior year's second half may still be unpaid when you close. It belongs on the settlement statement. Look for it.
2. You close in summer or early fall. The current year's bill does not exist yet. The seller's share is commonly prorated from the most recent bill, which is an estimate of a number nobody has seen. Your purchase agreement controls how that is handled. Ask your closing agent which figure was used.
3. You close after the bill is issued. The real number is known. The question becomes whether the first half was paid before closing, at closing, or is now yours to pay by the date on the notice.

In all three, the full bill for the year arrives addressed to whoever is on the tax record, and the treasurer expects it paid on the statutory dates regardless of how the buyer and seller split it between themselves. My post on how Montana property taxes are calculated covers the proration mechanics and the math behind the bill. If you are weighing an autumn purchase, the fall buying post covers what else a late-year closing changes.

What happens if a Montana property tax payment is late?

A late half becomes delinquent the moment the deadline passes. The statute adds a 2 percent penalty to the delinquent amount and charges interest at 5/6 of 1 percent a month until it is paid. If it stays unpaid, the county treasurer attaches a tax lien to the property no later than the first working day of the following August.

The penalty and interest rates are in MCA 15-16-102(3). Here is what they mean on a first half of $2,400, which is an illustration and not a typical Park County bill:

The dollars are modest. The consequences that come with them are the larger issue.

A tax lien. MCA 15-17-125 directs the treasurer to attach a lien by the first working day in August to property with delinquent taxes, after published notice and a mailed notice to the person assessed. The lien can be assigned to a third party. The owner and other interested parties can redeem it, generally by the first working day in August three years after it attached, under MCA 15-18-111. That is the general framework, and the statute has a shorter period for some vacant subdivided lots; the treasurer can give the exact date and payoff for a parcel. The Park County Treasurer posts the current delinquent tax list on its page.

The homestead rate. The Department of Revenue's homestead FAQ lists being current on all property tax payments as a condition of the reduced rate. In the department's words, current means "all past property taxes are paid," and "for 2026 taxes, you must have paid in full or made the first-half payment." A missed first half can put the lower rate at risk.

Not receiving the bill. MCA 15-16-101 says a failure to give notice of the tax due does not affect the legality of the tax. The tax is still owed, and nothing in the statute waives the penalty or interest because a bill went missing. Ask the treasurer how the office handles it.

One narrow grace period exists. For property that qualifies under the Property Tax Assistance Program, taxes paid within 20 calendar days of the due date carry no penalty or interest, per MCA 15-16-102(4)(b).

Why might the tax bill not reach a new owner?

The county treasurer mails the bill to the last-known address of the taxpayer, and the owner name and mailing address on the property tax record come from the Department of Revenue. After a sale, the record generally changes after the department processes the realty transfer certificate filed at closing. A fall closing can miss that year's mailing.

The chain has three links. Under MCA 15-7-305, the county clerk and recorder may not accept a deed for recording without a realty transfer certificate, and sends each certificate on to the department. Under MCA 15-7-304, the department is not required to change its ownership records until it has received that certificate. The treasurer then mails to the name and address the record shows when the bills are produced.

Three things go wrong often enough to plan for. The bill goes to the seller, who assumes it is no longer theirs. The bill goes to you, but at the property address, when your mail goes to a post office box or another state. Or the bill goes to you and to your mortgage servicer, and each assumes the other paid.

The fix is to stop relying on the mail alone. Park County's bills are searchable by owner name, address, or geocode on the county's online tax portal. Bookmark it and check it in the first week of November. In 2024 the treasurer told the Enterprise that paying online by credit card carried a 3 percent fee and an e-check carried a $2 fee; confirm the current fees on the portal before you choose.

Address changes for tax mail are made on a Department of Revenue form, not a county one. The Park County Treasurer's page links the form, tells owners to mail the completed form to the Department of Revenue, and lists the department's number as (406) 900-1020. The county page and the form give different return addresses, so call the department to confirm which office to use.

Does the homestead rate carry over when you buy a Montana home?

For the rest of the calendar year, yes. A home already enrolled for the homestead reduced rate keeps that rate through December 31 of the year it sells. Then it ends. The new owner has to enroll, and for tax year 2027 the Department of Revenue's enrollment period runs from May 4, 2026 through March 1, 2027.

This is the one I would put at the top of a new owner's list, because the gap between the two rates is large. For tax year 2026 the department's published rates are 0.76 percent on the first $378,000 of market value, 0.90 percent on the portion from $378,001 to $756,000, 1.10 percent on the portion from $756,001 to $1,511,999, and 1.90 percent on any portion over $1,512,000, for a principal residence or long-term rental that is enrolled and qualifies. The rates are incremental, so each applies only to its own slice of value. Residential property that does not qualify, or is not enrolled, is taxed at the flat 1.90 percent rate for 2026 on its full market value in most cases. The same department page lists one exception that matters in this county: a second home or short-term rental on a qualified agricultural parcel is taxed at a flat 1.35 percent.

On a home the department values at $600,000, the enrolled rate produces a taxable value of $4,870.80: $378,000 at 0.76 percent is $2,872.80, and the remaining $222,000 at 0.90 percent is $1,998.00. The flat rate produces $11,400, which is $600,000 at 1.90 percent. Those are taxable values, not bills; the bill is taxable value multiplied by the local mill levy, which varies by district. At this value the ratio holds wherever the home sits: the unenrolled home is taxed on about 2.3 times the taxable value. The ratio shifts with the home's value, and flat fees on the bill do not change with it.

What the department's homestead FAQ says about a purchase year:

• The home was enrolled before you bought it. Per the department's FAQ, the reduced rate stays in place through the end of that calendar year, even though ownership changed. To keep it, you enroll as the new owner. The statute behind this is MCA 15-6-405, which ends an approved rate at the end of the tax year in which ownership changes.
• The home was not enrolled. It is billed at the flat rate for that year. If it was your principal residence for at least seven months of the year, the department describes a refund of the difference, requested between January 1, 2027 and May 31, 2027 for tax year 2026, after the 2026 taxes are paid in full. A buyer who closes in fall 2026 will not reach seven months in the new home that year, so this route is open mainly to someone moving from another Montana principal residence with no gap, under the conditions the FAQ sets out. Paying in full also means paying the second half before the refund period closes, not on its last day.
• Either way, you enroll for 2027. Enrollment is through the department's enrollment page, online or by a paper form postmarked by March 1, 2027.

You can check whether a property is currently enrolled, before or after you buy it, with the department's enrollment verification tool and the property's geocode. The geocode is on the tax bill and on the Montana Cadastral map. My post on what $500,000 buys in Park County works the same math at a lower price and walks through the seven-month rule.

Eligibility has conditions beyond occupancy, including how title is held. Under the department's FAQ, a home owned by an LLC or an irrevocable trust does not qualify for the homestead rate, while a revocable grantor trust can when the grantor lives there. Whether your situation qualifies is a question for the department and your CPA, not for a blog post.

Who pays the property tax if you have a mortgage escrow account?

If your loan has an escrow account, the servicer collects a share of the tax with each monthly payment and pays the county on your behalf. The Consumer Financial Protection Bureau notes that the escrow payment changes when taxes change. The tax remains a lien on your property either way, so confirm it was paid.

The CFPB's explanation of escrow accounts covers the mechanics. Two Montana details sit on top of it.

First, the monthly payment option in MCA 15-16-122 is not available through a servicer. The statute says the treasurer may not accept a payment under the alternative schedule from a third-party escrow service, lender, or mortgage company. It is a tool for owners who pay the county themselves, the application is due to the treasurer by September 30 for the current year, and the treasurer may require automatic payments as a condition.

Second, a change in classification changes the escrow. If you bought a home that was enrolled for the homestead rate and you do not enroll for the following year, the next bill is computed at the flat rate. The servicer will usually catch the change at its next escrow review and adjust your monthly payment afterward. The reverse is also true: enrolling lowers a bill the servicer has been collecting toward at the higher figure.

The tradeoffs are plain, where the choice is yours; many loans require escrow. Escrow removes two deadlines from your calendar and gives up control over timing. Paying the county yourself keeps the money in your account until November and May and makes both deadlines yours. Paying the full year in November is the third option, and it ends the question until the next fall.

Which office handles which property tax problem?

Three offices share the work, and each one will send you to another if you start in the wrong place. The Department of Revenue sets value, classification, and the homestead rate. The county treasurer bills and collects. The county clerk and recorder records the deed and receives county tax appeal filings.

The Park County Treasurer says it directly on its page: the office does not deal with property appraisals or property values, and questions about a reassessment go to the Department of Revenue.

Value disputes run on a short clock. The department's informal review and appeal page gives 30 days from the date on a classification and appraisal notice to request an informal review, or to appeal directly to the county tax appeal board through the clerk and recorder. The Montana Tax Appeal Board makes the same point from the other side: the appeal period runs from the appraisal notice, not from the tax bill. MCA 15-7-102 lists a change in ownership among the events that trigger a new notice, so a new owner may receive one. The date printed on it starts the 30 days.

An appeal does not pause the due dates. To be eligible for a refund, the tax has to be paid under written protest before it becomes delinquent, under MCA 15-1-402. The department says a protest is valid only alongside a filed review request or appeal. The treasurer can explain how a written protest is filed, and a tax attorney or CPA can tell you whether one is worth filing.

One more local detail. Montana revalues residential property every two years under MCA 15-7-111. The department's notice explainer states that the value used for the 2025 and 2026 cycle is its estimate of market value as of January 1, 2024. What you paid in 2026 is not the number on the 2026 bill.

What dates belong on a new owner's tax calendar?

Seven dates cover most of a first year of owning in Montana. Put them in your phone the week you close, with a reminder two weeks ahead of each. One deadline is missing from the seven-date tax calendar because it has no fixed date: the 30 days that start when a classification and appraisal notice is issued.

The Property Tax Assistance Program line applies to fewer owners, but the deadline is firm: the department says an application that misses April 15 is considered for the following year.

What to do this week. Look up your property on the Park County tax portal by geocode or by your last name. Write down the name and mailing address shown on the record. If either is wrong, start the correction with the Department of Revenue now. It may not reach this fall's mailing, which is why the portal lookup matters more than the envelope. Then run the geocode through the homestead verification tool and write down whether the property is enrolled and for which tax year. Those two lookups take ten minutes and answer the two questions that cause the most trouble: where is the bill going, and at which rate.

The reason this works is that it replaces the mail with the record. The bill reflects what the county and the department have on file. If the file is right, a lost envelope costs you nothing, because you know the amount and the date without it. If the file is wrong, no amount of watching the mailbox will fix it.

Frequently Asked Questions

When are Montana property taxes due?

The first half is due by 5 p.m. on November 30 or within 30 days after the tax notice is postmarked, whichever is later. The second half is due by 5 p.m. on May 31. Both dates are set by MCA 15-16-102. When a due date falls on a Saturday or a holiday, the tax may be paid without penalty or interest by 5 p.m. on the next business day.

What is the penalty for paying Montana property taxes late?

Under MCA 15-16-102, a late payment is delinquent, a 2 percent penalty is added to the delinquent amount, and interest accrues at 5/6 of 1 percent a month until it is paid. If the tax stays unpaid, the county treasurer attaches a tax lien to the property no later than the first working day of the following August under MCA 15-17-125.

Do I still owe the penalty if I never received a tax bill?

Yes. MCA 15-16-101 says a failure to give notice of the tax due does not affect the legality of the tax. The county treasurer mails the bill to the last-known address on the property tax record. New owners can look up the bill by name, address, or geocode on the county's online tax portal and can ask the treasurer for the amount.

Can I pay Montana property taxes monthly?

The owner of a primary residence can apply to the county treasurer for a seven-payment schedule under MCA 15-16-122, with payments due at the end of each month from November 30 through May 31. The application is due by September 30 for the current year, the treasurer may require automatic payments, and the schedule cannot be paid by a mortgage servicer or escrow company.

Does the homestead reduced tax rate transfer to the buyer of a Montana home?

Only through the end of the calendar year of the sale. The Montana Department of Revenue's homestead FAQ says an approved reduced rate stays in effect for the property through the end of the current year even if ownership changes, and the new owner must submit a homestead application to continue it. For tax year 2027, enrollment closes March 1, 2027.

Who pays the property taxes in the year a Montana property sells?

The tax is a lien on the property that attaches each January 1 under MCA 15-16-403, so the bill follows the land. Buyer and seller commonly divide the year's tax between themselves at closing, and the split appears on the settlement statement. The county treasurer still expects the full amount on the statutory due dates from whoever owns the property.

How long do I have to appeal my Montana property tax valuation?

The Department of Revenue gives 30 days from the date on the classification and appraisal notice to request an informal review on Form AB-26 or to appeal directly to the county tax appeal board through the county clerk and recorder. The period runs from the appraisal notice, not from the tax bill, and taxes must be paid under written protest to preserve a refund.

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This article is general information, not legal, tax, or accounting advice. Stacy Bennin Real Estate is not a law firm or an accounting firm, and nothing here should be treated as advice from one. Laws, tax rules, and programs change, and they vary by state and by situation. Before acting on anything covered here, consult a licensed attorney and/or a certified public accountant in your state for current guidance on your specific circumstances.

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Two of the seven are payment due dates. The other five are deadlines that decide which rate you are taxed at, how you pay, and whether you can still dispute the value. If you are buying in Park County this fall or winter and want to know which of the seven applies to the property you are looking at, please reach out. It is a short conversation, and it is cheaper before closing than after the first notice.

Stacy Bennin is a licensed real estate broker in Montana, affiliated with Legacy Lands Real Estate in Paradise Valley. She helps buyers and sellers across Park County and southwest Montana find property that fits their needs, and stays current on AI and emerging technology so her clients benefit from where real estate is headed, not just where it has been. Reach her at stacybennin.com or (406) 224-3267.