Invoice Due Date Calculator

Last reviewed: October 14, 2026

Calculate the exact due date for any invoice payment term. Choose from Net 7 through Net 120, End of Month, Net 30/60 EOM, or business day variants; then enter your invoice date to see the result instantly.

When a due date falls on a weekend or public holiday, the calculator flags it and shows the next business day. Use the early payment discount field to display the discount deadline alongside the standard due date.

Invoice Date

Payment Terms

Holiday Calendar

Early Payment Discount (optional)

Discount % if paid within N days

Net 30 Calculator →Net 60 Calculator →Net 90 Calculator →Project Deadline Calculator →Late Payment Interest →

Worked example: one invoice under different terms

Take an invoice dated Tuesday, April 28, 2026 with the United States calendar selected; every date in this paragraph is computed by the calculator above. Net 30 counts 30 calendar days from the day after the invoice date and lands on Thursday, May 28, 2026, a business day. Net 30 EOM counts 30 days from the last day of the invoice month, April 30, and lands on Saturday, May 30, 2026; that is not a business day, so the calculator flags it and shows the next one, Monday, June 1, 2026. Thirty business days skip the weekends and Memorial Day (May 25) and end on Wednesday, June 10, 2026, 43 calendar days after the invoice date; on the Canadian calendar they skip Victoria Day (May 18) instead and end on Wednesday, June 10, 2026. Where a contract fixes no payment date, three laws set a 30-day period, each from its own starting point. Article 3 of the EU Late Payment Directive (2011/7/EU), in the text as it stood on 31 December 2020 that the UK's National Archives publishes, has Member States ensure that, in transactions between businesses, the creditor is entitled to late-payment interest once 30 calendar days have passed after the debtor receives the invoice. In the UK, under section 4 of the Late Payment of Commercial Debts (Interest) Act 1998, statutory interest starts to run the day after a 30-day period ends; that period begins with the later of the day the supplier performs and the day the purchaser has notice of the amount of the debt, or a later day where subsection (5A) applies. For US federal contracts, the general rule in FAR 32.904(b) makes an invoice payment due on the 30th day after the designated billing office receives a proper invoice, or the 30th day after government acceptance if that is later; paragraphs (c) to (f) of the section set other dates for architect-engineer, construction and cost-reimbursement service contracts and for certain food products.

Common pitfalls with payment terms

Three dating mistakes are worth checking for. First, Net 30 and Net 30 EOM are different terms: an invoice dated March 15 is due April 14 on Net 30 but April 30 on Net 30 EOM, 16 days later. Second, this calculator starts counting on the day after the invoice date; a contract that counts the invoice date as day one makes every due date a day earlier. Third, in the US a federal holiday observed on a Friday is not a Federal Reserve holiday: on Friday, July 3, 2026, most federal employees have the holiday for Independence Day, which falls on the Saturday, but the Federal Reserve Banks are open, so a payment system that follows the Fed's schedule treats the day as a business day while this calculator's US calendar does not.

What an early payment discount is worth

On terms that give 2 percent off for payment within 10 days and ask for the full amount within 30, paying on day 10 saves 2 percent for paying 20 days sooner. As a simple annual rate that is 2/98 × 365/20, about 37.2 percent, the formula this site's early payment discount calculator uses. To see the discount deadline beside the due date, enter the percentage and the number of days in the early payment fields above. The calculator counts those days in calendar days from the invoice date and does not move a deadline that lands on a weekend or holiday, so check the contract if yours does. For US federal agencies, the Treasury's Prompt Payment guidance also starts the discount period on the invoice date, when the invoice carries one.

For informational purposes only

This calculator provides general estimates based on business day counting rules. It does not constitute legal advice. Deadlines in legal, regulatory, or contractual matters may be subject to jurisdiction-specific rules, court orders, or statutory exceptions. Always verify critical deadlines with a qualified professional.

Frequently Asked Questions

What does Net 30 mean on an invoice?

This calculator reads Net 30 as a payment period of 30 days. Unless the contract says business days, it counts calendar days, starting the day after the invoice date. The 30-day period in Article 3 of the EU Late Payment Directive is counted in calendar days as well, from receipt of the invoice. If the contract says '30 business days', choose a business-day term instead.

What is Net 30 EOM?

In this calculator, Net 30 EOM (End of Month) counts 30 days from the last day of the month the invoice is dated in: an invoice dated March 15 is due April 30, March 31 plus 30 days. Contracts word month-end terms differently, so check where yours starts the count.

Is Net 30 calendar days or business days?

Unless the contract says otherwise, this calculator reads Net 30 as calendar days, as above. A contract that specifies '30 business days' gives a longer period: on a five-day week, 30 business days span six calendar weeks, 42 calendar days from a weekday start. Each public holiday on a working day inside the period pushes the due date to the next business day: at least one calendar day later, and three or more when a weekend lies in between. From Tuesday, April 28, 2026 on the US calendar it is 43 calendar days.

What happens if my invoice due date falls on a weekend or holiday?

If you're using business day terms, the due date automatically lands on a working day (weekends and holidays are skipped). For calendar day terms, the calculator flags non-business day due dates and shows the next available business day.

How do I see an early payment discount deadline?

Enter the discount percentage and the number of days it applies for in the early payment fields, for example 2 and 10 for a discount of 2 percent on payment within 10 days. The calculator shows the discount deadline beside the standard due date, counting calendar days from the invoice date. The terms on the invoice define the discount; the calculator only dates it.

Can I set custom payment terms?

Yes. Select 'Custom' from the payment terms dropdown, enter any number of days, and choose calendar or business days. This works for terms like Net 21, Net 45, or any duration your contract specifies.

Sources for these rules

Directive 2011/7/EU on combating late payment in commercial transactions, Article 3: 30 calendar days after receipt of the invoice where no period is fixed, and contractual periods over 60 calendar days only if expressly agreed and not grossly unfair (The National Archives (legislation.gov.uk), Official Journal text)
Late Payment of Commercial Debts (Interest) Act 1998, section 4: where no payment day is agreed the relevant day is the last day of the relevant 30-day period, and an agreed day later than the 60-day period does not stand unless it is not grossly unfair (The National Archives (legislation.gov.uk))
FAR 32.904, Determining payment due dates (U.S. General Services Administration)
Holiday Schedules: Reserve Banks close on the federal holidays and stay open on the Friday before a Saturday holiday (Federal Reserve Financial Services)
Federal Holidays: a Saturday holiday is observed on the preceding Friday (5 U.S.C. 6103(b)), a Sunday holiday on the following Monday (E.O. 11582, section 3(a)) (U.S. Office of Personnel Management)
Prompt Payment, Discounts on Payments: the invoice date starts the discount period (U.S. Department of the Treasury, Bureau of the Fiscal Service)

Checked October 11, 2026. All sources