Net 30 Invoice Due Date
Compute due dates for Net 15 / 30 / 60 / 90 invoices.
Written and maintained by Paul Clark, Redmoon Software · Rules last verified · Sources · Changes & corrections
These calculators are for informational purposes only and do not constitute legal, financial, or professional advice.
How the Net 30 Invoice Due Date works
The Net 30 Invoice Due Date calculator turns a start date and a payment term — Net 15, 30, 60, or 90 — into an exact due date. Net terms are counted in calendar days, so the tool simply needs the day the clock starts and the number of days in the term.
The ambiguity in Net 30 is never the 30; it is day zero. Invoice date, date of receipt, and delivery date can differ by days, and each shifts the due date. Agree on the start date up front and the due date stops being a point of dispute.
Worked example
An invoice dated May 2 on Net 30 terms is due May 32 — which does not exist, so the due date rolls to June 1. The calculator does that month-boundary arithmetic for you and shows the exact date.
Frequently asked questions
Is Net 30 counted in business days or calendar days?
Calendar days, in almost all cases. Net 30 means 30 calendar days from the agreed start date, so weekends and holidays are included in the count. The raw date can therefore land on a weekend — and by default the calculator does not leave it there: the next-business-day box is ticked, so a due date falling on a Saturday, Sunday, or a holiday on your selected calendar is moved to the next business day, and so is the end of an early-payment discount window if you enter one. That is the usual legal default where the contract is silent (N.Y. General Construction Law § 25 covers payment due on a day or within a period; California Civil Code § 11 covers holidays). Untick it when your contract makes the raw calendar date final.
What date does the term start from?
Whatever your agreement specifies — most commonly the invoice date, but sometimes the date the invoice is received or the goods are delivered. The calculator lets you set that start date explicitly.
Does it support Net 15, 60, and 90?
Yes. Choose any common net term and the due date is computed the same way.
What happens if the due date lands on a weekend?
By default the calculator moves it to the next business day, and an early-payment discount deadline with it. That is what accounts-payable runs do in practice and, where the contract is silent, what the law often provides: New York’s General Construction Law § 25 says a payment due on a weekend or holiday, or at the end of a period that ends on one, may be made on the next business day “with the same force and effect”, so no late interest runs for that gap. Untick the box if your contract makes the calendar date final.
Is Net 30 the same as one month?
No, and the gap is widest at month end. Thirty days from 31 January is 2 March in an ordinary year; one month from 31 January is 28 February. Contracts that use the two phrases interchangeably have built in a two-day ambiguity that only surfaces in February.
What this calculator does not do
A limitation you know about costs far less than one you find after the deadline. These are the specific things this tool cannot work out for you.
- Net terms are a contract term, not a law, for ordinary commercial invoices. The statutes above set defaults where nothing was agreed or where a public body is paying.
- Day zero is the ambiguity, not the 30. Invoice date, receipt date and delivery date can differ by days and each shifts the due date.
Where these rules come from
The periods this calculator applies are taken from the primary sources below rather than from secondary summaries. Verify against them before relying on a date that matters.
- N.Y. General Construction Law § 25
A contract payment due on a Saturday, Sunday or public holiday, or within a period ending on one, may be made on the next business day unless the contract indicates otherwise.
- California Civil Code § 11
An act a contract requires on a holiday may be performed on the next business day.
- UK — Late Payment of Commercial Debts (Interest) Act 1998
Where no term is agreed, sets a default payment period and a statutory interest entitlement.
- US — Prompt Payment Act, 5 CFR Part 1315
The 30-day rule that applies to US federal agency payments.
Related calculators
Payment Terms Calculator (2/10 Net 30)
Discount cutoff + net due date for early-payment terms.
OpenFreelance Invoice Scheduler
Schedule recurring invoices with due dates and reminders.
OpenLoan / Mortgage Payment Projector
Monthly loan payment dates, rolled to banking days when they fall at a weekend.
Open