ContractorHandbook

Late Fee on a $2,500 Invoice, 30 Days Overdue

Interest at 1.5% a month

$37.50

1.5% a month, simple interest charged pro rata by day, with no flat fee added.

Invoiceamount owedNow owedamount owedinterest for the months it has run lateamount x monthly rate x months late, plus any flat fee
A monthly percentage is an annual rate wearing a smaller number, and stating both is what makes the charge stick. The page gives the daily figure too, because that is the sentence that gets an invoice paid.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Unpaid invoice amount2500 $
  • Late fee rate you wrote in the contract1.5 % per month
  • Days past due30
  • Flat fee, if your contract has one0 $

Now owed$2,537.50

Original invoice$2,500.00
Days late30 (1 months)
Interest at 1.5% a month$37.50
Flat fee$0.00
Total now due$2,537.50
Annual rate this equals18%
Per day from here$1.25

Days past due compared

Interest is simple and pro rata by day, so it climbs in a straight line rather than accelerating.

Days past dueNow owedTotal now due
30 days$2,537.50$2,537.50
60 days$2,575.00$2,575.00
90 days$2,612.50$2,612.50
120 days$2,650.00$2,650.00

What else matters here

Thirty days late on $2,500 is $37.50 of interest at 1.5 percent a month. The invoice becomes $2,537.50 and grows $1.25 every day it stays open.

This is the size where a late invoice starts to hurt cash flow rather than just annoy. Two and a half thousand dollars is a material order, and material orders do not wait for the customer to feel like paying.

Send the figure, do not threaten it. An invoice reissued with the interest line already calculated and dated is a document. A message saying you will have to start charging interest is a negotiation you just opened against yourself.

What this calculator assumes

  • A late fee is only collectable if it was in the contract or on the invoice before the invoice went late. A fee that first appears in a reminder email is not enforceable anywhere.
  • 1.5 percent a month is 18 percent a year and is the common trade figure, but states cap this. Several cap it below 18 for consumer work, and a rate over the cap can void the whole fee clause, not just the excess.
  • Interest here is simple, charged pro rata by day. Compounding monthly is legal in some states and not others, so the simple figure is the safe one to put on paper.

Questions people ask

What is the late fee on a $2,500 invoice at 30 days?

$37.50 at 1.5 percent a month, making $2,537.50 due in total.

Can I charge a late fee if it was not in the contract?

No. A late fee is only collectable if it was in the contract or printed on the invoice before that invoice went late. A fee that first appears in a reminder email is not enforceable anywhere, however overdue the money is.

Is this simple interest or compound?

Simple, charged pro rata by day. Compounding monthly is legal in some states and not in others, so the simple figure is the safe one to put on paper and the one this calculator uses.

Different numbers?

The late fee calculator takes any dimensions you like and hands back the same list.

Other common sizes