Late Fee on a $15,000 Invoice, 30 Days Overdue
Interest at 1.5% a month
$225.00
1.5% a month, simple interest charged pro rata by day, with no flat fee added.
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 amount15000 $
- Late fee rate you wrote in the contract1.5 % per month
- Days past due30
- Flat fee, if your contract has one0 $
Now owed$15,225.00
| Original invoice | $15,000.00 |
|---|---|
| Days late | 30 (1 months) |
| Interest at 1.5% a month | $225.00 |
| Flat fee | $0.00 |
| Total now due | $15,225.00 |
| Annual rate this equals | 18% |
| Per day from here | $7.50 |
Days past due compared
Interest is simple and pro rata by day, so it climbs in a straight line rather than accelerating.
| Days past due | Now owed | Total now due |
|---|---|---|
| 30 days | $15,225.00 | $15,225.00 |
| 60 days | $15,450.00 | $15,450.00 |
| 90 days | $15,675.00 | $15,675.00 |
| 120 days | $15,900.00 | $15,900.00 |
What else matters here
Fifteen thousand dollars 30 days past due carries $225 of interest, a total of $15,225, and $7.50 a day. Left for six months it reaches $1,350.
When a customer genuinely cannot pay it all at once, a written payment plan beats both a lawsuit and a series of broken promises. Set out the amounts and the dates, say that interest continues to accrue on the outstanding balance, and include a line saying the whole remaining amount becomes due immediately if a payment is missed.
Get it signed, even if it is one page. A signed schedule turns a disputed invoice into an acknowledged debt with a payment history attached, which is a far stronger position if it ever does reach a lawyer. And take the first payment at the moment of signing rather than on the first scheduled date, because a plan whose first payment is in the future is a promise, not a plan.
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 $15,000 invoice at 30 days?
$225 at 1.5 percent a month, so $15,225 is due and it rises $7.50 a day.
Should I accept a payment plan on an overdue invoice?
Often yes, in writing. A signed schedule with dates, continuing interest and an acceleration clause is stronger than a series of verbal promises.
What makes a payment plan enforceable?
A signature, stated amounts and dates, a line saying interest continues, and a clause making the balance due immediately on a missed payment. Take the first payment at signing.
The late fee calculator takes any dimensions you like and hands back the same list.