US freelance late fees, what to charge

Ask a UK freelancer what to charge on a late invoice and they'll cite chapter and verse of the Late Payment of Commercial Debts Act. Ask a US freelancer and you'll usually get some variation of "I dunno, is it eighteen percent?" That's because unlike the UK, the United States has no single federal statute setting a late-payment rate for private business debts. It's mostly contract-based, patchworked with state usury caps.

Here's how to think about it without getting into trouble.

The convention: 1.5% per month, 18% APR

The default that shows up in most US B2B invoicing templates and accounting software is 1.5% per month, or 18% APR. It's not law. It's just a well-established contract convention, and enforceable in most states if it's in your written agreement or on the invoice before the client agreed to pay.

The math is simple interest on the outstanding balance from the day after the invoice due date:

late fee = amount × (annual_rate / 100) × (days_overdue / 365)

On a $2,000 invoice that's 45 days late at 18% APR:

2000 × 0.18 × (45 / 365) = $44.38

Not a fortune. But it compounds every month, and more importantly, it changes the client's incentives.

Skip the mental maths. Use our free US Late Fee Calculator → — switch the jurisdiction dropdown to "United States" to work out what a specific client owes you today.

State usury caps you should know about

Every state has a usury law that caps how much interest you can charge on private debts. Most cap somewhere between 10% and 25% APR for business-to-business debts. A few examples:

California: 10% APR max on non-consumer loans without a written contract. With a written contract signed by both parties, most B2B late fees at 18% are enforceable.
New York: 16% APR default cap. Higher rates require a specific written agreement.
Texas: 6% APR default without a contract; up to 18% with a written agreement; higher rates possible under specific commercial-code provisions.
Florida: 18% APR is the typical enforceable ceiling on B2B debts.

Bottom line: if your invoice or master agreement clearly states the late-fee percentage, and the rate isn't wildly above local convention, you're generally fine. But verbal or "implied" late fees are almost impossible to enforce. Put it on the invoice, and ideally in the signed engagement letter.

Flat late fees are also fair game

Some freelancers skip the percentage entirely and charge a flat fee per invoice past a grace period — $25 or $50 is common for small projects, $100+ for larger ones. Advantages:

Easier to communicate. "There's a $50 late fee 15 days past due" is unambiguous.
Doesn't get lost in rounding. A $30 interest charge on a small invoice feels petty. A flat $50 is a decision.
You can combine it with interest. Flat fee kicks in at day 15, interest starts accruing at day 30.

Our calculator supports both — enter your APR and an optional flat fee.

The escalation ladder that actually gets paid

Charging a late fee is legal in most cases. Collecting it is a different problem. Here's the sequence that works better than a single stern email:

Day 0 (invoice sent): your invoice clearly states the payment terms, the late-fee policy, and the payment methods you accept. This is the moment you earn the right to enforce.

Day 5–7 after due date: a friendly nudge. No mention of fees. "Just checking in — did the invoice from [date] make it to the right person?" You'd be amazed how often the answer is "no, we forwarded it to the wrong inbox."

Day 14 after due date: firmer, still cordial. Reference the payment terms explicitly. Mention that late fees begin accruing on day 30 if that's what your terms say.

Day 30 after due date: apply the late fee. Send a revised invoice showing the original amount plus the fee, itemised. Don't apologise for the fee — it's in the contract. Do offer a payment plan or a short extension if they ask.

Day 45–60: escalate. Talk to the specific person handling the payment. If the client is a company, get past accounts payable to your actual contact. Threaten (politely) to pause work.

Day 60+: final notice. Referral to a collection agency, small claims court, or writing off. In most US states, small claims court handles claims up to $10,000 and doesn't require a lawyer.

The point isn't the escalation itself, it's that most invoices get paid at step 2 or 3, not step 5. You just need a system that reliably fires the reminders at every step.

What Tallylark actually does with this

Tallylark automates the whole escalation ladder without you having to remember what day it is. You set the schedule once (e.g. "friendly nudge on day 5, firmer at day 14, late fee applied at day 30") and it handles every reminder, itemises the late fee on the pay page, and lets your client pay directly. You get paid faster. You also stop being the person who has to write awkward payment-chase emails.

You still get to decide whether to charge the fee on a given invoice — but you never have to remember to send the reminder.

The one thing that beats every late-fee strategy

Put the terms on the invoice. Every invoice. Every time. In writing.

More than half the "unenforceable late fee" arguments a client will throw at you come from a genuinely-held belief that they never agreed to one. Make it impossible to argue.