Montana Late Fee Calculator
Your late fee
$62.50
Paid 12 days late; the lease has no grace period.
- Days past due
- 12 days
- Grace period ends
- No grace period
- Earliest fee date
- September 29, 2026
- Lease late fee
- 5% of $1,250.00 = $62.50
- Rent + late fee
- $1,312.50
Montana: MCA title 70, chapter 24 contains no late fee provision, so there is no legal cap or waiting period to apply; only your lease terms count.
Next step: turn these figures into a late rent notice for the tenant.
Montana rent late fee law
Montana's landlord and tenant act, MCA title 70, chapter 24, contains no late fee provision; late fees appear only in the Act's definition of rent, and nothing in it limits a late rent fee or gives a grace period.
Read in full for this check: Montana Residential Landlord and Tenant Act of 1977 (Montana Code Annotated, title 70, chapter 24). Official source · checked .
Late rent notice builder
Before you send it: this builds a reminder letter about overdue rent and a late charge. It is not an eviction notice. A notice to pay rent or quit is a separate document, and Montana has its own rules for it. Nothing on this page is legal advice.
[Your name or company]
Date: October 10, 2026
To: [Tenant name]
[Rental property address]
Re: Overdue rent for [Rental property address]
Dear [Tenant name],
This letter is a reminder that the rent of $1,250.00 for [Rental property address] was due on September 28, 2026. As of October 10, 2026, $1,250.00 of it is still unpaid (12 days past due).
Your lease provides for a late charge, which comes to $62.50.
Amount now due
- Unpaid rent
- $1,250.00
- Late charge
- $62.50
- Total
- $1,312.50
Please pay $1,312.50 at your earliest opportunity.
If this letter crossed with your payment, please disregard it.
Regards,
[Your name or company]
How to use the Montana rent late fee calculator
- Enter the monthly rent and the rent that is overdue.
- Enter the date the rent was due and the date it was paid, or today if it is still unpaid.
- Choose how the lease sets the late fee (percent of rent, flat amount or dollars per day) and type the figure from the lease.
- Enter the grace days written in the lease.
- Read the late fee and the earliest fee date, then copy the figures or print a late rent notice.
Work out interest on an overdue B2B invoice under Montana law. The legal default rate — what applies when the contract is silent — is 10%, and the statute is quoted verbatim below. All math runs locally in your browser.
Legal rate after the money becomes due (instruments, accounts stated, settled accounts) when no written rate is fixed.
Late fee breakdown
- Interest owed
- —
- Daily rate
- —
- Total (invoice + interest)
- —
Still unpaid? Generate a formal demand letter — it computes the interest and cites Montana's statute (MCA 31-1-106, 31-1-107) for you.
Worked example: Montana invoice interest at 10%
Interest at Montana's statutory default of 10% a year, worked out with the same formula as the calculator above: amount × (10% ÷ 365) × days. If your contract states its own rate, enter that rate in the calculator instead.
| Invoice amount | 30 days late | 60 days late | 90 days late |
|---|---|---|---|
| $1,000.00 | $8.22 | $16.44 | $24.66 |
| $5,000.00 | $41.10 | $82.19 | $123.29 |
| $10,000.00 | $82.19 | $164.38 | $246.58 |
What Montana law says about invoice interest
Parties may agree in writing to the payment of any rate of interest that does not exceed the greater of 15% or an amount that is 6 percentage points per year above the prime rate published by the federal reserve system in its statistical release H.15 [...] dated 3 business days prior to the execution of the agreement.
Quoted verbatim from the linked official source — not our paraphrase. How we source and re-check every row is documented in the data methodology.
Maximum late fee in Montana — written B2B contracts
Hard cap 15% (floor).
Cap = greater of 15% or Fed H.15 prime +6 pts; no broad business exemption (only regulated lenders escape). Prime+6 is below 15% now, so 15%/yr binds ordinary B2B.
Basis: Mont. Code Ann. § 31-1-107. Compare all 51 jurisdictions in the maximum late fee by state table and cap-regime map.
Rent and invoices follow different laws — consumer debt is not covered
The Invoice tab, the rate card and the statute sections on this page are about business-to-business invoices. Residential rent late fees live in Montana's landlord-tenant law. Montana: MCA title 70, chapter 24 contains no late fee provision, so there is no legal cap or waiting period to apply; only your lease terms count. Consumer credit has separate, stricter rules. The distinction is explained in B2B invoice late fees vs. residential rent.
Use this data
Montana's row — rate, cap, citation, verbatim quote, verification date — is part of our open 51-jurisdiction dataset: CSV · JSON (CC BY 4.0, cite myinvoicetemplate.com). Set late-fee terms on your next invoice with the free invoice generator, or state them clearly using the wording guidance in the payment terms guide.
Montana late fee FAQ
Is there a legal limit on rent late fees in Montana?
Montana's landlord and tenant act, MCA title 70, chapter 24, contains no late fee provision; late fees appear only in the Act's definition of rent, and nothing in it limits a late rent fee or gives a grace period. Read in full for this check: Montana Residential Landlord and Tenant Act of 1977 (Montana Code Annotated, title 70, chapter 24), checked 2026-10-03. The late fee and grace days in the lease decide.
How do I work out a late fee on rent in Montana?
Enter the monthly rent, the overdue amount, the date the rent was due and the date it was paid, then the late fee in the lease (a percent of rent, a flat amount or dollars per day) and its grace days. The calculator gives the late fee, the earliest fee date and rent plus fee, and turns them into a late rent notice.
Can I charge late fees on overdue invoices in Montana?
Yes — on business-to-business invoices. If your contract or invoice states a late-fee rate, that rate governs (subject to the cap rules below). If nothing was agreed: 10%. Legal rate after the money becomes due (instruments, accounts stated, settled accounts) when no written rate is fixed. Statute: MCA 31-1-106, 31-1-107, verified 2026-08-19. Consumer and rent debts follow separate laws.
What is the maximum late fee on a B2B invoice in Montana?
For a written B2B contract: Greater of 15% or Fed H.15 prime +6 pts (dated 3 business days before signing) — prime +6 is currently below the 15% floor, so 15% governs. Basis: Mont. Code Ann. § 31-1-107. The full cap analysis is on the Invoice (B2B) tab; this covers business-to-business deals only — consumer credit has stricter separate caps.
What interest applies if my contract doesn't mention late fees in Montana?
The statutory default rate of 10%. Legal rate after the money becomes due (instruments, accounts stated, settled accounts) when no written rate is fixed. Statute: MCA 31-1-106, 31-1-107 (verbatim quote on this page, verified 2026-08-19).
Where does this data come from, and when was it verified?
Every invoice-interest figure on this page comes from our 51-jurisdiction dataset: each row researched against the controlling statute or the state's official current-rate page, independently re-checked, and stamped with its own verification date — Montana's row was last verified 2026-08-19. The operative legal text is quoted verbatim on this page with a link to the official source, the methodology is public, every verification pass is logged in the changelog, and the full dataset is downloadable (CC BY 4.0).
Not legal advice. This page summarizes Montana's commercial-interest statute for general information, with the verification date shown above — it tells you when we last confirmed the figures, not that they are still current today. Statutes change and courts interpret them; verify the cited statute at the official source, or ask a licensed attorney in your state, before charging a late fee or demanding interest.