How to Charge a Late Fee on an Invoice (With Wording)

To charge a late fee on an invoice, state the fee in your contract and on your invoices before work starts, apply it only after the due date passes, and add it as a separate line on the overdue invoice.

A late fee gives clients a reason to pay on time and compensates you for waiting. But it only works if the client agreed to it in advance and the amount is allowed where you do business. This guide covers the types of late fees, how to calculate one, wording you can copy and how to add it to an invoice.

Can you charge a late fee on an invoice?

Yes, if the client agreed to it before the work started and the fee is allowed under your state's law. The safest way to make it enforceable is to put it in your contract, proposal or estimate, and repeat it on every invoice.

A late fee added for the first time on an overdue invoice is hard to collect and can damage the relationship. Clients pay fees they knew about; they dispute fees that surprise them.

How much can you charge for a late fee?

It depends on your state and on whether your client is a consumer or a business. Many states limit late fees or interest on overdue balances, and the limits can differ for consumer and commercial accounts. Some states also cap the interest rate you can charge.

Before you set a rate, check your state's rules or ask an attorney. This is general information, not legal advice. When in doubt, a modest flat fee or a small monthly percentage is less likely to be challenged than a large one.

What types of late fees can you charge?

The common types are a flat fee, a monthly percentage, a one-time percentage and a daily fee. Flat fees and monthly percentages are popular because they're easy to explain.

Type	How it works	Example on a $2,000 invoice	Best for
Flat fee	A fixed amount once the invoice is late	$25.00	Small invoices, simple terms
Monthly percentage	A percent of the unpaid balance for each month late	1.5% per month = $30.00 per month	Larger invoices, business clients
One-time percentage	A percent of the balance, charged once	5% = $100.00	Short-term projects
Daily fee	A small amount each day the invoice is late	$2.00 per day	Rare; can add up fast and draw disputes

The example rates above show how the math works. They are not legal limits, so confirm what your state allows before you use any of them.

How do you calculate a late fee?

Multiply the unpaid balance by the agreed rate for each period it's late, or add the agreed flat fee. Here are two worked examples for a $2,000 invoice due April 14.

Monthly percentage (1.5% per month):

• Paid within the first month after the due date (by May 14): $2,000 × 1.5% = $30.00 late fee.
• Paid in the second month (May 15 to June 14): $2,000 × 1.5% × 2 = $60.00 late fee.

Flat fee ($25):

• Paid any time after April 14: $25.00 late fee, charged once.

Whether a partial month counts as a full month, and whether the fee compounds, depends on the terms you wrote. Keep it simple and spell it out. To run the numbers for your own invoice, use the free late fee calculator.

What wording should you use for a late fee?

Use plain, specific wording that names the amount, when it starts and how often it applies. Put it in three places: your contract or proposal, your invoice terms and your late reminders.

In your contract or proposal:

Invoices are due within 15 days of the invoice date. Balances not paid by the due date are subject to a late fee of 1.5% per month on the unpaid amount, starting the day after the due date.

On every invoice:

Payment due by April 14. A late fee of $25.00 applies to payments received after the due date.

In a reminder after the due date:

Invoice INV-0042 for $2,000.00 was due on April 14. As stated in our agreement, a late fee of 1.5% ($30.00) now applies, bringing the balance to $2,030.00. You can pay here: [link].

As a line item on the invoice:

Late fee, 1.5% of $2,000.00 for April 15 to May 14: $30.00

Our payment reminder email templates show where the late fee fits into each stage of follow-up.

How do you add a late fee to an invoice?

Add the fee as its own line, with a description that shows the rate and the period, then update the balance due. Don't hide it in another line or change the original prices.

1. Confirm the invoice is past due and the fee is in your agreed terms.
2. Calculate the fee for the time that has passed.
3. Add a line such as "Late fee, 1.5% for April 15 to May 14."
4. Update the total and balance due.
5. Send the updated invoice with a short, polite note that explains the charge.

Invoicefy doesn't add late fees automatically. If a late fee applies, add it to the invoice yourself as a line item, as described above. Invoicefy does send automatic email reminders 2 days before the due date and 3 and 7 days after, which often gets the invoice paid before a fee is needed.

Should you waive a late fee?

Sometimes. Waiving a first late fee for a good long-term client can buy a lot of goodwill, especially if they apologize and pay right away. Say so in writing: "I've waived the late fee this time as a courtesy." That keeps your terms in place for next time.

Hold firm when a client is late again and again. The fee exists for exactly that situation.

Do late fees actually get clients to pay faster?

Late fees help most as a deterrent, when clients see them before they're late. Once an invoice is badly overdue, a polite call or a payment plan often works better than adding more charges. The best approach combines clear terms, a deposit, short payment terms and steady reminders.

For the full approach, see our guide on how to get paid faster. If you need a clean invoice layout with a spot for late fee terms, start from the free invoice templates.