Invoice due date calculator

How to calculate an invoice due date

1. Enter the invoice date. Use the issue date on the invoice. It is today’s date by default, and you can change it.
2. Choose the payment terms. Pick Net 7, 14, 15, 30, 45, 60 or 90, due on receipt, end of month (EOM), EOM plus days, or a custom number of days or business days.
3. Choose what happens at weekends. Leave the date as it is, or move it to the next Monday or the previous Friday if the due date falls on a Saturday or Sunday.
4. Read the due date. You get the due date in long form, the day after (when late interest can start) and the days left or overdue.
5. Put it on the invoice. Write the due date on the invoice, not only the terms. “Net 30” plus a clear date leaves less room for argument.

How due dates are worked out

A due date is the day by which the customer has to pay. Most invoices state it as a number of days after the invoice date, for example “Net 30”, which means the full amount is due 30 days after the invoice date. The calculator does that count for you and handles the cases that cause arguments: end-of-month terms, month ends with different lengths and due dates that land on a weekend.

The clock normally starts on the invoice date. Some contracts start it on the date the invoice is received or on the date of delivery or acceptance. Check your contract. If the due date depends on receipt, the calculator’s “Invoice date” field should hold the date of receipt.

Counting rules the calculator uses

• Net N: invoice date plus N calendar days. The day of issue is day 0.
• EOM (end of month): the last day of the month in which the invoice is dated.
• EOM + N: N days after the last day of the invoice month. “Net 30 EOM” is the usual name.
• Business days: N working days, Monday to Friday, skipping weekends but not public holidays.
• On receipt: due on the invoice date.

Common payment terms and what they mean

Terms are explained further on our payment terms page, which also covers early-payment discounts such as “2/10 net 30”.

What to do when the due date is a weekend or holiday

If a due date lands on a Saturday or Sunday, the customer’s bank cannot process the payment until Monday. Rules vary: some contracts say that the next working day is the due date, and others do not mention it at all. The calculator offers three choices:

• Keep the date – the strict date counted from the invoice date.
• Next Monday – gives the customer the next working day. This is common in B2B practice.
• Previous Friday – asks for the money before the weekend. This is stricter.

The calculator does not know your local public holidays. If a bank holiday falls on the due date, add a day yourself.

Why the due date matters for late fees and interest

Late payment rights start from the due date. In the UK, statutory interest under the Late Payment Act begins on the day after the due date, which the calculator shows as “Late interest can start”. Our UK late payment interest calculator takes the due date as the starting point.

In other countries, the rules and rates differ, and in many places you need a contract clause for a late fee. A due date that is clear on the invoice is the foundation of any reminder or claim: a vague “payable promptly” gives you nothing to point to.

Tips to get paid on time

• State the exact due date on the invoice, not only “Net 30”.
• Send the invoice immediately when the work is complete. Every day of delay moves the due date.
• Send it to the person who approves payment, not just to the person you worked with.
• Choose shorter terms for new clients, for example Net 14 or a deposit.
• Add payment details, accepted methods and a payment link.
• Diarise a reminder for the day before the due date and for the day after it.

See how to get paid faster for more.

Mistakes with due dates

• Counting from the wrong date. Check whether your contract says invoice date, receipt date or delivery date.
• Confusing “Net 30” with “30 days from month end”. They differ by up to a month.
• Forgetting that months differ. 30 days from 31 January is not the end of February.
• No due date on the invoice. The customer then picks a date.
• Agreeing very long terms without checking the law. Some countries cap B2B terms; for example, the EU Late Payment Directive sets 60 days as a general limit unless expressly agreed and not grossly unfair.

Glossary

Net 30

Payment is due 30 days after the invoice date.

EOM

End of month; the due date is counted from the end of the invoice month.

Due on receipt

Payment is expected as soon as the invoice is received.

Business day

A working day, normally Monday to Friday, excluding public holidays.

Grace period

Extra days after the due date before a late fee is applied.

Related topics

• invoice due date calculator
• net 30 calculator
• net 60
• EOM payment terms
• end of month terms
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• business days calculator
• due on receipt
• payment terms
• late payment date
• invoice terms
• days until due