Subject: Late fee applied — invoice [#1234] updated balance

Hi [CLIENT NAME],

As outlined in our agreement ([Net 30], late fee of [1.5]% per month),
a late fee of [$FEE] has been applied to invoice [#1234], now [X] days
overdue. The updated balance is [$TOTAL].

I'll waive the fee if payment of the original amount [$AMOUNT] arrives
by [DATE — 3-5 days out]. After that the full updated balance applies.

Best,
[YOUR NAME]
Tip: calculate the exact fee at https://late-fee-calculator.surge.sh
