Late-fee calculator
What an overdue balance costs if you charge a yearly rate.
How we calculate
Late fee = principal × annual rate × days / (100 × 365). That is simple interest on the overdue slice only. It is not compound, and it does not restart the original sale. If the customer owed ₹8,000 and is 15 days past the due date at 24 percent a year, the extra is ₹78.90. Write that as its own line so the original due stays readable.
Charge it only when you already said you would
A late fee that appears for the first time at the door is a different product from the one they took. Agree the yearly rate when you sell, print it on the invoice or the pay link, and use this page so both of you see the same days and the same rupees. If you never agreed a rate, skip the fee and collect the principal. Rent is not collected by surprising people.
This is a planning tool, not legal advice and not a court document. Confirm the rate and the day-count with whoever keeps your books before you treat the figure as final.
Frequently asked questions
What is a late fee on shop credit?
A charge you add because the due date passed. This calculator uses simple interest on the overdue principal for the extra days, at the yearly rate you already agreed.
What formula does it use?
Late fee = principal × annual rate × days / (100 × 365). Fifteen days late on ₹8,000 at 24 percent a year is ₹78.90, not a round ₹100.
Is this the same as the interest calculator?
Same family of arithmetic, different job. Interest is “what does this balance cost over a period you chose.” Late fee is “they already missed the due date, here is the extra.”
Can I charge a late fee if we never agreed a rate?
You can ask. You will not collect. Write the rate on the sale, on the invoice, or on the khata page the customer can see. A surprise rate at the door is how udhar turns ugly.
Do the extra days include the due date itself?
Count calendar days after the due date. If they owed it on the 1st and paid on the 16th, that is 15 days in this box.
Should I add GST on the late fee?
That depends on how you invoice and on your accountant. This tool only returns the fee. It does not split CGST or IGST on top.
What if they pay a part of the due?
Run the calculator on the amount that is still late, not on the original sale. A part payment should shrink the principal before you charge the extra days.
Can I use 30 days in a month instead of 365?
This site uses 365 so a year of daily fees adds up to the yearly rate you typed. A 360-day bank year will come out a few rupees different. Say which calendar you are using before you argue.
Does anything get uploaded?
No. The numbers stay in the browser. There is no account on this page.
Will a court accept this number?
No. It is a planning figure so both of you can see the same arithmetic. A dispute belongs with whatever you both signed, not with a web page.
Can I send this to the customer?
Yes. Open it on your phone, type their numbers, and show the screen or screenshot the result into WhatsApp. Do not screenshot their whole khata.
What rate should I type?
The rate you already told them. Eighteen percent a year is a common planning figure on shop credit. Do not invent a higher one because they are late today.
Does the signed-in ledger charge this automatically?
The ledger stores the due. It does not silently add a late fee. You decide, you show the number, you record it as a line if they agree.