Late Fee on a $4,000 Invoice, 30 Days Overdue
Interest at 1.5% a month
$60.00
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 amount4000 $
- Late fee rate you wrote in the contract1.5 % per month
- Days past due30
- Flat fee, if your contract has one0 $
Now owed$4,060.00
| Original invoice | $4,000.00 |
|---|---|
| Days late | 30 (1 months) |
| Interest at 1.5% a month | $60.00 |
| Flat fee | $0.00 |
| Total now due | $4,060.00 |
| Annual rate this equals | 18% |
| Per day from here | $2.00 |
Days past due compared
Interest is simple and pro rata by day, so it climbs in a straight line rather than accelerating.
| Days past due | Now owed | Total now due |
|---|---|---|
| 30 days | $4,060.00 | $4,060.00 |
| 60 days | $4,120.00 | $4,120.00 |
| 90 days | $4,180.00 | $4,180.00 |
| 120 days | $4,240.00 | $4,240.00 |
What else matters here
Four thousand dollars 30 days past due carries $60, for a total of $4,060, rising $2 a day. At 60 days it is $120.
Partial payments are where a late invoice quietly turns into a mess. A customer with three open invoices sends $4,000 with no reference, and unless the contract says otherwise it is not always obvious which one it paid. Say in the contract that payments are applied to the oldest balance first, and send a statement after every payment showing what was applied where, so the running total is never a matter of opinion.
Be careful with a short check marked paid in full. In many states cashing it can be treated as accepting the lesser amount as settlement of a disputed debt, which extinguishes the rest. If a check arrives short with words like that on it, do not deposit it until you know the rule in your state, because the deposit can cost far more than the difference.
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 $4,000 invoice at 30 days?
$60 at 1.5 percent a month, so $4,060 is due and it rises $2 a day.
How should partial payments be applied?
To the oldest balance first, stated in the contract, with a statement after each payment showing what was applied to which invoice.
Can I cash a check marked paid in full for less than I am owed?
Be careful. In many states depositing it can be treated as settling a disputed debt in full, which wipes out the rest. Check your state rule before it goes in the bank.
The late fee calculator takes any dimensions you like and hands back the same list.