Montana Late Fee Calculator

No cap no late fee section in the law we read
Rent limit
None in MCA title 70, chapter 24
Earliest fee day
–
Statute
MCA title 70, chapter 24
Checked
What was not paid on time. Copies the rent until you type here.
How the lease sets the late fee
How many days the lease gives before a late fee; 0 if none.

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
October 20, 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.

Late rent notice builder

10% legal default rate (contract silent)
Max written B2B rate
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.
Cap regime
Hard cap — 15% (floor)
Statute
MCA 31-1-106, 31-1-107
Verified
— how we verify · changelog

Legal rate after the money becomes due (instruments, accounts stated, settled accounts) when no written rate is fixed.

Pre-filled with Montana's statutory default (10%), which governs only when the contract names no rate; a rate stated in your contract replaces it.

Interest at 10% a year

Interest owed on an overdue invoice in Montana at 10% per year
Invoice amount30 days late60 days late90 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

Maximum late fee in Montana — written B2B contracts

Hard cap 15% (floor).

Basis: Mont. Code Ann. § 31-1-107.

About this page

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 .

Before you send the late rent notice: it is a reminder letter about overdue rent and a late charge, 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.

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.
— Mont. Code Ann. § 31-1-107(1). Read it at the official source · row verified 2026-08-19.

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.

Not legal advice. Figures were last verified on the date shown; check the cited statute before charging a late fee.