The Standard Late Fee on an Invoice Is 1.5% a Month, Until You Do the Math

The usual numbers, and why 'standard' is the wrong word

Ask ten accountants and most will tell you the same thing. Small businesses usually charge 1% to 1.5% per month on the overdue balance, or a flat fee of $25 to $50 per late invoice. A monthly 1.5% rate works out to 18% a year when it is not compounded.

That is a convention, not a rule. No federal law in the US says what a business may charge another business for paying late. The number you see repeated online is just what lots of invoice templates and accounting tools happen to suggest by default.

Three things decide what your late fee should actually be:

• Where you and your client are. Some places set the rate for you (the UK and EU do, for business clients). Many US states cap how much interest or late charge you can add, and the cap can differ for consumers and businesses.
• Who your client is. A body shop billing a fleet company is in a different position from a wedding photographer billing a couple. Rules tend to be stricter when the client is an individual.
• What the client agreed to. In most of the US, a late fee you never mentioned before the work started is very hard to collect. More on that next.

So the honest answer to "what is the standard late fee" is: 1.5% a month is common, a flat $25 to $50 is common, and neither one is worth much unless it was on the quote or contract.

A late fee only counts if the client agreed to it first

This is the part most people get wrong. They send an invoice, it goes 30 days overdue, and they add a line that says "Late fee: $40." The client never saw that term before. In most US situations, that fee is a request, not a debt.

A late fee is a contract term. For it to stick, it should appear somewhere the client accepted before you started: the signed quote, the contract, or the booking terms they ticked. Printing it on the invoice alone is too late, because the invoice comes after the work is done and the deal is already made.

If you already send written quotes, the fix is one sentence in your terms. Our guide on how to send a quote to a client shows where payment terms sit, and the quote template and email setup has a terms block you can paste this into.

The invoice should then repeat the same term, word for word, so nobody can claim surprise. Our piece on what a small business invoice should look like covers where the due date and terms go.

One exception worth knowing: in the UK, a business client owes statutory interest on a late payment even if your contract says nothing about it. That is the law filling the gap, not a fee you invented. In the US there is no general equivalent for private businesses.

And if the question in your head is really "does the client still have to pay the invoice itself," that is a separate issue. The answer is almost always yes, and we covered the exceptions in yes, you still owe a late invoice.

Where the law sets the number for you

United Kingdom, business clients

The Late Payment of Commercial Debts (Interest) Act 1998 lets you claim interest at 8 percentage points above the Bank of England base rate, plus a fixed compensation amount per invoice: £40 for debts under £1,000, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more. It applies to business-to-business sales, not to consumers. The base rate moves, so check the current figure before you calculate.

European Union, business clients

The EU Late Payment Directive (2011/7/EU) sets statutory interest at the central bank's reference rate plus at least 8 percentage points, and a minimum fixed compensation of €40 per late invoice. Each country writes this into its own law, so the details vary slightly.

United States

There is no single number. Late fees and interest are governed by state law, and each state handles it differently. Some states have usury laws that cap interest rates. Some have specific rules for late charges in consumer contracts. Commercial (business-to-business) agreements are often treated more loosely than consumer ones, but not everywhere.

Courts in every state also apply a general test: a late fee has to be a reasonable estimate of what late payment costs you, not a punishment. A fee that looks like a penalty can be thrown out entirely. A $500 late fee on a $600 invoice is the kind of thing that fails.

If you bill the federal government, the Prompt Payment Act sets the interest agencies owe you on late payments, at a rate the Treasury publishes every six months. Many states have their own prompt payment rules for state agencies, and some for construction.

How to find your own cap

Search "[your state] maximum interest rate late payment" and look for your state legislature or attorney general's site, not a blog. If you bill individuals, also search "[your state] consumer late fee." Better still, spend half an hour with your accountant or a local business attorney once, get the number, and put it in your terms. That is a one-time cost, not an ongoing one.

A common safety clause is "or the maximum rate permitted by law, whichever is lower." It does not make an unreasonable fee reasonable, but it stops a slightly-too-high rate from sinking the whole term.

Percentage or flat fee: the math nobody shows you

Here is where the default advice falls apart for small businesses. On a percentage fee, the amount scales with the invoice. On a flat fee, it does not. That means each one wins at a different invoice size.

At 1.5% a month, one month late on a $1,000 invoice is $15. On $500 it is $7.50. A $25 flat fee charges more than 1.5% on any invoice under $1,667 ($25 ÷ 0.015). Above that, the percentage starts to bite harder.

So if most of your invoices are a few hundred dollars (a dog groomer, a tutor, a mobile mechanic doing small jobs), a 1.5% monthly fee is almost meaningless. Nobody changes their behavior to avoid $6. A flat $25 is noticeable.

If your invoices run to $8,000 (a contractor, a landscaper doing a full install), a flat $25 is pocket change against the balance. A 1.5% monthly charge on $8,000 is $120 a month, and that gets attention.

Some businesses use both: a flat fee once the invoice is late, then a monthly percentage if it stays unpaid. That can be fine, but check it against your state's rules, because stacking charges is exactly the kind of thing that starts to look like a penalty.

Now the uncomfortable part. Work out what chasing costs you. Take the time you spend on a late invoice (emails, a phone call, re-sending, checking the bank) and multiply by what an hour of your time is worth. If you spend 90 minutes chasing and your time is worth $60 an hour, that is $90. A 1.5% fee on a $1,200 invoice is $18. The fee does not cover the chase. Its value is in getting paid on time in the first place, not in what it earns you once someone is already late.

Five mistakes that make a late fee useless or unenforceable

1. Adding it only on the invoice. Covered above, but it is the most common one. If it was not on the quote or contract, expect a fight you will probably lose.
2. Compounding it. Charging 1.5% on last month's fee as well as the balance makes the math messy and can push you over a state cap quickly. Charge simple interest on the original overdue amount.
3. Charging it the day after the due date with no warning. Legally you may be allowed to, but clients who forgot by a day and get hit with a fee often pay the invoice and never book again. A short grace period (say 5 to 7 days) with a reminder before the fee applies costs you little and keeps the relationship.
4. Making it a punishment. A fee wildly out of proportion to the invoice, like $200 on a $350 job, invites a court to call it a penalty and refuse it. It also invites a one-star review.
5. Waiving it silently. If you never actually charge it, clients learn it is decoration. If you choose to waive it, say so in writing: "I've waived the late fee this time; it will apply from next invoice." That keeps the term alive.

A sixth, smaller one: vague wording. "Late payments may incur fees" tells the client nothing. Name the amount, when it starts, and how it is calculated.

What I would actually set up

Take a wedding photographer, call her Dana, who books $3,200 packages with a $1,000 deposit and the $2,200 balance due 14 days before the wedding. Her quote and contract would say:

Payment is due by the date shown on each invoice. Any balance unpaid 7 days after its due date will be charged a late fee of 1.5% per month (18% per year) on the overdue amount, or the maximum rate permitted by law, whichever is lower.

On a $2,200 balance, one month late is $33. That is enough to notice, not enough to look like a penalty, and the 7-day grace period handles the client who simply forgot.

A mobile dog groomer with $85 visits would write something different: a flat $15 late fee on any invoice unpaid 7 days after the due date. A percentage on $85 would be about $1.28 a month, which is pointless.

Then the order of operations:

• Put the term in your quote or contract and get it signed or accepted.
• Repeat the same wording on every invoice, next to the due date.
• Send a friendly reminder a few days before the due date, and another the day it passes.
• When the grace period ends, send a revised invoice showing the fee as its own line, with the calculation.
• If you waive it, say so in writing.

You can do this with any decent invoicing tool. If automatic late-fee calculation matters most to you, QuickBooks Online and FreshBooks both have built-in late fee settings and are a good fit. If you also want the quote, contract, invoice and reminder emails living in one place, Fynl carries the same terms from quote to contract to invoice and can send the reminder emails on a schedule through your Gmail. It does not send text reminders yet, so if your clients only respond to SMS, use a tool that does.

If you take card payments, a Stripe payment link that tells you who paid on every reminder removes one more excuse for paying late.

Questions people also ask

Sources

• GOV.UK: Late commercial payments, charging interest and debt recovery
• EUR-Lex: Directive 2011/7/EU on combating late payment in commercial transactions
• U.S. Treasury Bureau of the Fiscal Service: Prompt Payment
• Cornell Law School LII: Liquidated damages