Late fee and interest calculator
What's owed
in interest.
First reminder email (free)
Subject:
Why I made this
Chasing invoices is the worst part of freelancing. The first email is easy to put off because it feels awkward, and by the time you send it you're annoyed, and it shows. Having the whole sequence ready in advance, getting firmer on a schedule, makes it boring in a good way.
The Late-Payment Chaser Kit
$9, one-time
- 11 ready-to-send messages: heads-up before the due date, friendly, firm, late-charge notice, pause-work notice, payment plan offer, final notice, and replies for "it's being processed", disputes and thank-you.
- A chase schedule that says what to send on which day, and what to check first.
- Payment-terms and late-fee clause templates for your next contract, with official references for the UK and New York State. Not legal advice.
- An invoice tracker (CSV) that works out days late, interest, and the next message to send.
Instant download after checkout. Markdown and CSV files that work in Google Sheets, Excel and any email app.
How it's calculated
Simple interest: amount × yearly rate ÷ 365 × days late. A monthly rate is treated as 12 times that rate per year. The flat fee is added once the invoice is at least one day late.
Check: gov.uk's own example is £1,000 at 8.5% (8% plus a 0.5% base rate) for 50 days. That's £85 a year, about 23p a day. The calculator shows £11.64; gov.uk rounds the daily figure to 23p first and gets £11.50.
Not legal advice. Whether you can charge interest or a late fee, and how much, depends on your contract, where you and your client are, and whether the client is a business or a consumer. Check your agreement and local rules, or ask a lawyer.