How to Charge Late Fees on Invoices (With Wording)

Late payment is one of the most common problems freelancers face, and most freelancers handle it the same way: they wait, they send an awkward "just checking in," and they absorb the cost. A late fee changes the incentive. It tells clients that your payment terms are real, and it compensates you for the cash you're carrying on their behalf.

A late fee only works if it's set up correctly, though. Added after the fact, it looks like a penalty invented in anger — and in many places it isn't enforceable at all. This guide covers how to set one up properly, what to charge, the exact wording to use, and how to apply it without damaging the relationship.

The short answer

• Agree it before the work starts. Put the late-fee terms in your contract or proposal and repeat them on every invoice. A fee the client never agreed to is hard to justify and often impossible to enforce.
• Keep it proportionate. A common range is 1–2% of the unpaid balance per month, or a modest flat fee. Many jurisdictions cap what you can charge.
• Use a grace period. A few days after the due date avoids penalizing a payment run that was a day late.
• Be consistent. Apply it the same way every time, or waive it deliberately — never randomly.

Step 1: Put the terms in your contract

The late fee belongs in the agreement the client signs, not just on the invoice. That's what makes it a term both sides agreed to rather than a surprise.

A clear clause covers four things: when payment is due, how long the grace period is, how the fee is calculated, and whether it repeats.

Contract clause you can adapt:

"Invoices are due within 14 days of the invoice date. If an invoice remains unpaid 7 days after its due date, a late fee of 1.5% of the outstanding balance will be added, and a further 1.5% for each additional 30 days the balance remains unpaid."

If you use proposals, include the same terms there too. Clients sign proposals more readily than long contracts, and it keeps the payment terms in front of the person who approved the budget. Our guide to deposits, milestones and payment terms covers the rest of the terms worth agreeing up front.

Step 2: Choose what to charge

There are two common models.

Some freelancers combine them: a flat fee once, then a monthly percentage if the invoice stays unpaid.

Whatever you choose, keep it proportionate. The point is to change behaviour, not to punish. An excessive fee is more likely to be challenged, harder to enforce, and more likely to end the relationship.

Check your local rules

What you're allowed to charge depends on where you and the client are. A few well-known examples — always check the current rules for your situation:

• UK: For business-to-business debts, the Late Payment of Commercial Debts (Interest) Act 1998 lets you claim statutory interest at 8% above the Bank of England base rate, plus fixed compensation depending on the size of the debt, even if your contract says nothing about late payment.
• EU: The Late Payment Directive (2011/7/EU) gives businesses a right to interest on late commercial payments — at least 8 percentage points above the European Central Bank reference rate — plus a minimum of €40 in compensation for recovery costs.
• US: Rules vary by state, and many states cap interest rates. A contractually agreed, reasonable fee is standard practice, but check your state's limits.

If you work with clients in other countries, or the amounts involved are significant, a short consultation with a local accountant or lawyer is money well spent.

Step 3: Put the wording on every invoice

Repeat the terms on the invoice itself, near the total and due date. This is a reminder, not a threat, so keep the tone neutral.

Invoice footer wording:

"Payment due within 14 days. Invoices unpaid 7 days after the due date incur a late fee of 1.5% of the outstanding balance per month, as agreed in our contract."

Shorter version:

"Due: 14 days. Late fee: 1.5% per month after a 7-day grace period."

When a fee is applied, add it as its own line item — for example, "Late fee (1.5% of $3,200 overdue balance)" — and send an updated invoice. Never quietly change the original amount. A separate line keeps the record clear for both of you.

Step 4: Remind before you charge

Most late payments aren't deliberate. The invoice went to the wrong person, sat in an approval queue, or got buried. A short reminder sequence recovers most of them before a fee is ever needed:

1. A few days before the due date: a friendly heads-up with the invoice attached.
2. On the due date: a short note that payment is due today.
3. A few days after: a direct but polite reminder that mentions the grace period.
4. When the grace period ends: notice that the late fee has been applied, with the updated invoice.

Reminder when the fee is about to apply:

"Hi Sam — a quick note that invoice #0142 for $3,200 was due on 3 March. Per our agreement, a 1.5% late fee is added after 7 days, so if payment arrives by 10 March no fee will apply. The pay link is below. Thanks!"

For more templates, see how to get clients to pay on time.

Step 5: Decide when to waive it

Waiving a fee can be good business. A long-standing client who's always paid on time and had one late invoice will remember that you were reasonable. The key is to waive it deliberately and say so:

"I've waived the late fee this time as a thank-you for being such a great client — the invoice below shows the original amount."

What hurts is inconsistency — charging one client and silently skipping another. If you have a policy, apply it; if you make an exception, make it visible.

Common mistakes

• Adding a fee the client never agreed to. This is the most common mistake and the one most likely to start a dispute.
• Charging during the grace period. If your terms say seven days, charge on day eight.
• Changing the original invoice amount. Add a new line instead.
• Letting it slide for months, then charging a large fee. Apply terms promptly and consistently.
• Charging while a payment is in transit. If a client tells you they've paid by bank transfer, confirm before adding anything.

How Twin-Gig helps

Twin-Gig lets you set a late-fee policy once — a percentage or flat fee, with a grace period — and attaches those exact terms to each invoice when it's sent, so an invoice is never charged a fee it didn't state. Reminders go out on a schedule in your own voice, the fee is applied as its own line after the grace period, and you can waive it in one click. If a client says they've already paid, reminders and fees pause until you confirm.

The result is that you spend less time chasing, and your clients always know exactly where they stand.

Sources and further reading

On this blog

• How to Get Clients to Pay on Time (Stop Chasing Invoices)
• Deposits, Milestones & Payment Terms Every Freelancer Needs
• Freelance Invoicing in 2026: Templates & Getting Paid Faster

External sources

• Late commercial payments: charging interest — GOV.UK
• A user's guide to the recast Late Payment Directive (2011/7/EU) — UK Department for Business