Accounts Receivable & Cash Collection

Invoice Late Fee & Interest Calculator

When clients pay late, your cash flow suffers. Calculate late payment penalties, daily accrued interest, and copy battle-tested email reminder templates that get invoices settled fast.

1. Overdue Invoice Details

Original Invoice Amount

Days Past Due Date

days

One-Time Late Fee Penalty

Flat fee specified in contract terms (e.g. $50).

Annual Interest Rate (APR)

Industry standard is 1.5% per month (18% APR) or statutory state limit.

Invoice Reference Number

Total Outstanding Balance

$4,612.11

Including 28 days of accrued interest

Original Principal Amount	$4,500.00
Flat Late Penalty Fee	$50.00
Daily Interest Rate	0.0493%/day
Accrued Interest Charges	$62.11

Copy-Paste Client Reminder Email