Guides 3 min read Updated February 15, 2026

Late Payment Interest for Freelancers: The Complete Guide

Your client is 30 days late. Can you charge them extra? The short answer is: **Yes, but you need to do it right.**

The Rule: Put it in the contract

You cannot legally enforce a late fee if the client never agreed to it. The best place to do this is in your initial contract or on the invoice itself **before** they accept the work.

Standard Late Fee Clause:

"Invoices not paid within 30 days of the invoice date are subject to a 1.5% monthly late fee."

How to calculate interest

Most freelancers charge between **1.5% and 2% per month**. This equates to about 18-24% per year (APR).

**Formula:**

(Invoice Amount) x (Monthly Interest Rate) = Late Fee

**Example:**
Invoice: $1,000
Late Fee (1.5%): $15
Total Due: $1,015

Should you actually charge it?

This is the tricky part. Charging a $15 late fee might annoy a client enough that they stop working with you.

**Strategy:** Use the late fee as leverage, not revenue.

When a client is late, say:
*"Technically, there is a late fee on this invoice as per our contract. However, if you can pay by Friday, I'm happy to waive the fee."*

This makes you look generous while still applying pressure.


Automate the reminder, prevent the fee

The goal isn't to collect late fees; it's to get paid on time.

**Followio** ensures your clients receive polite, automated reminders before the due date, so you rarely have to have the "late fee conversation".

Get paid on time, every time

Stop calculating interest and start automating your invoices.

Late Payment Interest Calculator Guide (How to charge clients) - Followio