Free calculator
Invoice due date calculator
Pick the invoice date and the payment terms. The calculator counts the days and tells you the due date and the day of the week.
Due date
30 October 2026
- Day of the week
- Friday
- Days from the invoice date
- 30
How due dates are counted
Payment terms count calendar days from the invoice date, weekends and holidays included. An invoice dated 1 March on 30-day terms is due on 31 March.
Print the due date on the invoice itself, not just the terms, so there is no argument about when payment was expected.
The 45-day rule for MSMEs
If you are a micro or small enterprise registered on Udyam, the MSMED Act, 2006 requires buyers to pay you by the agreed date, and never later than 45 days after accepting the goods or services (15 days when nothing was agreed).
Pay later and the buyer owes compound interest at three times the RBI bank rate. Since the 2023–24 tax year, buyers also cannot deduct such late payments as an expense until they actually pay (section 43B(h) of the Income-tax Act). Both give you leverage: show your Udyam number and the terms on your invoice.
Last updated 2026-09-30. This calculator is a guide, not tax advice.
Frequently asked questions
What does “Net 30” mean?
Payment is due 30 days after the invoice date. “Net 15” is 15 days, “due on receipt” means immediately.
Can I agree payment terms longer than 45 days with a buyer?
If you are a micro or small enterprise, the MSMED Act caps the agreed period at 45 days; longer terms don’t stop interest running after day 45.
Should I count from the invoice date or the delivery date?
Terms normally run from the invoice date. Under the MSMED Act the clock runs from the day the buyer accepts the goods or services, which is usually the delivery date.