Washington State Late Fee Calculator
Your late fee
$62.50
Check the statute
Paid 12 days late, after the 5-day grace period.
The Washington rule is not a simple cap: only its earliest fee day is applied here, so compare your fee with the statute text below.
- Days past due
- 12 days
- Grace period ends
- October 3, 2026
- Earliest fee date
- October 4, 2026
- Lease late fee
- 5% of $1,250.00 = $62.50
- Rent + late fee
- $1,312.50
Washington, earliest legal fee date: October 4, 2026
Next step: turn these figures into a late rent notice for the tenant.
Washington State rent late fee law
Washington State, RCW 59.18.170(2): rent paid no later than five days after it is due cannot carry a late fee. If it is paid later than that, the landlord may count late fees from the day after the due date up to the day of payment.
(2) The landlord may not charge a late fee for rent that is paid within five days following its due date. If rent is more than five days past due, the landlord may charge late fees commencing from the first day after the due date until paid.
Manufactured/mobile home lots in Washington State
This applies to manufactured/mobile home lot agreements made or renewed from May 7, 2025 on: under such an agreement, rent that arrives no later than five days after the due date cannot be charged a late fee, and the monthly late fees are limited to 2% of the total rent in the first month the rent is past due, 3% in the second month in a row and 5% in the third and following months; when rent is more than five days late they may count from the day after the due date.
(2) Any rental agreement executed between the landlord and tenant shall not contain any provision: [...] (j) Allowing the landlord to charge a late fee for rent that is paid within five days following its due date for leases or rental agreements entered into or renewed on or after May 7, 2025. If rent is more than five days past due, the landlord may charge late fees commencing from the first day after the due date until paid. During the first month that rent is past due, late fees may not exceed two percent of the tenant's total rent per month. During the second consecutive month that rent is past due, late fees may not exceed three percent of the tenant's total rent per month. During the third consecutive month and all subsequent consecutive months that rent is past due, late fees may not exceed five percent of the tenant's total rent per month.
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 Washington 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 Washington State 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 Washington State (RCW 19.52.010) law. The legal default rate — what applies when the contract is silent — is 12%, and the statute is quoted verbatim below. All math runs locally in your browser.
Legal rate where no different rate is agreed in writing; applied as prejudgment interest on liquidated claims.
Late fee breakdown
- Interest owed
- —
- Daily rate
- —
- Total (invoice + interest)
- —
Still unpaid? Generate a formal demand letter — it computes the interest and cites Washington's statute (RCW 19.52.010, 19.52.020) for you.
Worked example: Washington State invoice interest at 12%
Interest at Washington's statutory default of 12% a year, worked out with the same formula as the calculator above: amount × (12% ÷ 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 | $9.86 | $19.73 | $29.59 |
| $5,000.00 | $49.32 | $98.63 | $147.95 |
| $10,000.00 | $98.63 | $197.26 | $295.89 |
What Washington law says about invoice interest
(1) Except as provided in subsection (2) of this section, every loan or forbearance of money, goods, or thing in action shall bear interest at the rate of twelve percent per annum where no different rate is agreed to in writing between the parties [...]
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 Washington State — written B2B contracts
No statutory cap
Business entities can't plead usury, and no one may plead it for a commercial/business/investment/agricultural-purpose deal — so B2B may exceed the 12% floating cap freely.
Profit and nonprofit corporations, Massachusetts trusts, associations, trusts, general partnerships, joint ventures, limited partnerships, and governments and governmental subdivisions, agencies, or instrumentalities may not plead the defense of usury nor maintain any action thereon or therefor, and persons may not plead the defense of usury nor maintain any action thereon or therefor if the transaction was primarily for agricultural, commercial, investment, or business purposes: PROVIDED, HOWEVER, That this section shall not apply to a consumer transaction of any amount.
Basis: RCW 19.52.080. 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 Washington's landlord-tenant law. On the Rent tab, RCW 59.18.170(2) is checked against your lease figures and quoted in full. Consumer credit has separate, stricter rules. The distinction is explained in B2B invoice late fees vs. residential rent.
Use this data
Washington'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.
Washington State late fee FAQ
Is there a legal limit on rent late fees in Washington State?
Washington State, RCW 59.18.170(2): rent paid no later than five days after it is due cannot carry a late fee. If it is paid later than that, the landlord may count late fees from the day after the due date up to the day of payment. Source: RCW 59.18.170(2), checked 2026-10-03; the Rent tab quotes it word for word.
When can a landlord charge a late fee in Washington State?
Not before day 6 after the rent was due (RCW 59.18.170(2)). Enter the due date and the lease's grace days in the calculator to get the earliest date a fee may be charged.
How do I work out a late fee on rent in Washington State?
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 Washington?
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: 12%. Legal rate where no different rate is agreed in writing; applied as prejudgment interest on liquidated claims. Statute: RCW 19.52.010, 19.52.020, verified 2026-08-19. Consumer and rent debts follow separate laws.
What is the maximum late fee on a B2B invoice in Washington?
For a written B2B contract: Floating cap: higher of 12% or 26-week T-bill average +4 pts — business transactions are exempt (any agreed rate). Basis: RCW 19.52.080. 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 Washington?
The statutory default rate of 12%. Legal rate where no different rate is agreed in writing; applied as prejudgment interest on liquidated claims. Statute: RCW 19.52.010, 19.52.020 (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 — Washington'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). For rent, the Rent tab quotes RCW 59.18.170(2) word for word, links its source and gives the date it was checked (2026-10-03).
Not legal advice. This page summarizes RCW 59.18.170(2) and Washington'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.