Free Tool

Late Fee Calculator

Calculate the total amount due on an overdue invoice, including any late fees and monthly interest. Useful for sending payment reminders that include a real, defensible total.

Calculate the total now due

$100$1,500$20,000
130 days180
$0$25$200
0%1.5%3%

Total amount due

$1,547.50

$1,500

original

$25

flat late fee

$22.50

interest charges

Stop chasing late invoices.

Kairvio sends invoices via text with one-tap pay links. Late fees auto-apply per your terms. Most customers pay same-day.

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What's a fair late fee for service businesses?

Standard late fee structures most service businesses use:

  • $25–$50 flat fee for invoices that go past due, plus
  • 1–1.5% monthly interest on the outstanding balance.

State usury laws cap how high you can go. Most states allow up to 1.5% per month (18% annualized). A few states are stricter — check your state's commercial usury rate before setting a higher number.

The single most important thing: put the late fee policy in writing on the invoice and in the original estimate. Late fees that aren't disclosed up front are difficult to enforce and damage customer relationships. See our service agreement template for example language.