ContractorHandbook

Late Fee on a $12,000 Invoice, 30 Days Overdue

Interest at 1.5% a month

$180.00

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 amount12000 $
  • Late fee rate you wrote in the contract1.5 % per month
  • Days past due30
  • Flat fee, if your contract has one0 $

Now owed$12,180.00

Original invoice$12,000.00
Days late30 (1 months)
Interest at 1.5% a month$180.00
Flat fee$0.00
Total now due$12,180.00
Annual rate this equals18%
Per day from here$6.00

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$12,180.00$12,180.00
60 days$12,360.00$12,360.00
90 days$12,540.00$12,540.00
120 days$12,720.00$12,720.00

What else matters here

Twelve thousand dollars at 1.5 percent a month is $180 in 30 days and $12,180 due, growing $6 a day. By day forty five it is $270.

Once an invoice this size passes about forty five days, email has done what email can do. Email creates a record and a record is necessary, but it does not create a commitment, because nobody has to answer it and it is easy to leave until tomorrow. A phone call is harder to avoid and it produces an actual sentence: a date, an amount, or a reason.

Do both, in order. Call, ask when it will be paid and how much, stay quiet long enough for the answer, then send a short email the same hour that says thank you for the call, here is what we agreed and here is the date. That email is now a record of a promise rather than a request, and it is the single most useful document in any collection that later gets serious.

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 $12,000 invoice at 30 days?

$180 at 1.5 percent a month, making $12,180 due and $6 a day after that.

Should I call or email about an overdue invoice?

Both. Call to get a date and an amount out of somebody, then email the same hour confirming what was agreed. The call creates the commitment, the email records it.

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