Invoice Due Date Calculator
Enter the invoice date and choose the payment terms. The calculator adds the term's calendar days to the invoice date — 30 days for Net 30, 15 for Net 15, none for due on receipt — and shows the due date and how many days away it is. If your agreement moves weekend due dates, it can move a Saturday or Sunday due date to the following Monday.
How to calculate an invoice due date
- Start from the date the term counts from — usually the invoice date. Your agreement may name another, such as the date the invoice is received.
- Add the days in the term, counting every calendar day, weekends included: 30 for Net 30, 15 for Net 15.
- Check the weekday. If the result is a Saturday or Sunday and your agreement moves weekend due dates, use the next business day.
- Write the date on the invoice, not only the term, so there is no doubt about the day payment is due.
What does Net 15 mean?
Net 15 means the full invoice amount is due 15 calendar days after the invoice date. An invoice dated 1 October 2026 on Net 15 terms is due on 16 October 2026.
What does Net 30 mean?
Net 30 generally means payment is due 30 calendar days after the invoice date, unless the agreement names a different starting date. "Net" refers to the full amount of the invoice. An invoice dated 1 October 2026 on Net 30 terms is due on 31 October 2026.
What does Net 45 mean?
Net 45 means payment is due 45 calendar days after the invoice date — about six and a half weeks. An invoice dated 1 October 2026 on Net 45 terms is due on 15 November 2026.
What does Net 60 mean?
Net 60 means payment is due 60 calendar days after the invoice date, roughly two months. In some countries the law limits how long payment terms between businesses can be, so check the rules that apply to you before agreeing to long terms.
What does "Due on receipt" mean?
Due on receipt means payment is due as soon as the client receives the invoice, with no extra days in the term. It is common for deposits and small jobs. Writing a date next to it on the invoice makes it clear from which day the invoice is overdue.
What happens if the invoice due date falls on a weekend?
Net terms count calendar days, so a due date can land on a Saturday or Sunday, and nothing in the term itself moves it. Some agreements say a due date on a weekend or public holiday moves to the next business day; others say nothing. If yours is silent, agree with your client which applies. The calculator above can show either: keep the calculated date, or move a weekend date to the following Monday.
Invoice due date examples
For an illustrative invoice dated Thu, 1 Oct 2026. The dates are worked examples, not a rule for any market or country.
| Payment term | Counting | Due date | Moved to next business day |
|---|---|---|---|
| Due on receipt | On the invoice date | Thu, 1 Oct 2026 | No change |
| Net 7 | Invoice date + 7 days | Thu, 8 Oct 2026 | No change |
| Net 15 | Invoice date + 15 days | Fri, 16 Oct 2026 | No change |
| Net 30 | Invoice date + 30 days | Sat, 31 Oct 2026 | Mon, 2 Nov 2026 |
| Net 45 | Invoice date + 45 days | Sun, 15 Nov 2026 | Mon, 16 Nov 2026 |
| Net 60 | Invoice date + 60 days | Mon, 30 Nov 2026 | No change |
Invoice payment terms
The due date on an invoice should follow the payment terms you and your client agreed in the quotation or contract, not a term chosen when the invoice is sent. Freelance payment terms explains what to agree before work starts: deposits, milestones, the due date for each invoice and what happens if payment is late. Write the due date on the invoice next to the term, for example "Net 30 — due 31 October 2026"; in the free invoice generator, the notes field is the place for it.
What to do when an invoice becomes overdue
Send a short reminder the working day after the due date that names the invoice number, the amount and the due date, and ask for a payment date. The payment reminder email templates cover the heads-up before the due date through to a final notice, and the overdue invoice email templates are organised by how late the invoice is. The free payment reminder email generator writes one from your invoice details. If reminders don't work, how to follow up on an unpaid invoice covers the next steps; for a UK business client, the UK late payment calculator shows the statutory interest that may apply.
Frequently asked questions
How do I calculate an invoice due date?
Add the number of days in the payment term to the invoice date, counting every calendar day. For Net 30 on an invoice dated 1 October 2026, the due date is 31 October 2026. If your agreement moves weekend due dates, a Saturday or Sunday due date moves to the following Monday.
What does Net 30 mean on an invoice?
Net 30 generally means the full invoice amount is due 30 calendar days after the invoice date. Some agreements count from a different day, such as the date the invoice is received or the end of the month, so check what yours says.
Does Net 30 include weekends?
Yes. Net terms normally count calendar days, so weekends and public holidays are included. Only a term written in business or working days skips them. What happens when the due date itself falls on a weekend depends on the agreement between you and your client.
What is the difference between Net 15 and Net 30?
Only the number of days. Net 15 is due 15 calendar days after the invoice date and Net 30 is due 30 days after it. A shorter term means you are paid sooner; some clients pay on a fixed monthly cycle and ask for a longer one.
What does due on receipt mean?
Due on receipt means payment is due as soon as the client receives the invoice, with no extra days in the term. Writing a specific date on the invoice next to it makes it clear from which day the invoice is overdue.
What should I do if a client does not pay by the due date?
Send a short reminder the working day after the due date that names the invoice number, the amount and the due date, and ask for a payment date. If it stays unpaid, follow up more firmly and check what your agreement allows next, such as a late fee or pausing work.
Track the invoice after it is sent
Once an invoice is created in DealInSec, it is tracked as paid, pending or overdue, and DealInSec can draft a payment reminder from the invoice details — number, amount, due date and days overdue. It only drafts: you review the reminder and send it yourself. The free plan and a 7-day trial with no card are open in every country; paid plans can currently be bought in India only.
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