Free Creator Tool

Free Late Payment Interest Calculator for Freelancers & Creators

Enter your invoice amount, how many days it's overdue, and your agreed interest rate. Find out exactly how much you're owed — and what to put on your follow-up invoice.

Invoice Details

The amount your client owes before interest.

$

How many days past the due date?

days

Check your contract or use your country's statutory late payment rate.

8%

• Typical freelance contracts: 5–10%

• ~8% (common statutory rate in some regions)

Follow-up Email Template

Use this template to chase your client based on the exact calculations above.

Hi team, I’m writing to follow up on my invoice for $2,500.00, which is now 30 days overdue. As per my standard terms (8% annual interest), a late fee of $16.44 has been added, bringing the new total to $2,516.44. Could you please provide an updated timeline on when this will be processed? Thanks, [Your Name]
You're owed
30 days overdueThis is when late fees typically start compounding

$2,516.44

Original $2,500.00 +$16.44 in late fees

Your invoice increases by $0.55/day until paid

Interest accrued$16.44
Daily rate$0.55 / day
Annual rate applied8%
If unpaid in 60 days$2,532.88
If unpaid in 90 days$2,549.32

If you don't track invoices, you'll keep chasing payments manually.

Use cases

  • Send a clear late fee total in follow-up emails.
  • Calculate monthly interest for Net 30 invoices that are past due.
  • Reference the exact amount owed before sending a payment chase email.

FAQ

What interest rate should I use?

Many creators use 1% to 1.5% per month, but your contract terms should define the rate. Add it to your invoices using the invoice generator.

Is late interest legal?

It is legal when agreed in writing. Include late fee terms in your contract or invoice so expectations are clear.

How do I follow up professionally?

Use a structured reminder sequence. The payment chase template is a good starting point.

How late payment interest is calculated

Late payment interest is calculated using simple daily interest: take your annual interest rate, divide by 365 to get a daily rate, then multiply by the number of days the invoice is overdue and the original invoice amount. The formula is: Interest = Principal × (Annual Rate ÷ 365) × Days Overdue. This matches the approach used in most contracts and statutory late payment legislation worldwide.

What interest rate should I use?

The rate depends on what's in your contract. If you specified a late payment clause (e.g. "1.5% per month" or "8% per annum"), use that rate. If your contract is silent, many countries have a statutory rate you can fall back on — in the UK this is 8% above the Bank of England base rate for business-to-business invoices. In the US, rates vary by state. For creators doing brand deals, building a late payment clause into your standard terms is one of the most effective ways to get paid faster. If you need help sending a professional invoice with clear terms, use our free invoice generator.

How to charge a client for late payment

  • Send a formal follow-up invoice. Issue a new invoice referencing the original, with the interest amount added as a separate line item. Keep the original invoice number on it for clarity.
  • Reference your contract. In the email, explicitly cite the late payment clause from your original agreement. This removes ambiguity and makes the charge undeniable.
  • Escalate in writing, not verbally. Always chase payment by email so you have a paper trail. If the situation escalates to small claims court, this documentation is essential.
  • Know when to stop and write it off. Interest accruing doesn't help if the client simply doesn't pay. After 60–90 days, consider whether mediation or a collections agency is appropriate.

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