Net 15 payment terms: meaning, due date

Net 15 at a glance

Type

Net terms

Full amount due

15 days after the invoice date

Also written

N15, n/15

Example dates

Average amount owed to the supplier

Paying on the due date, about 15 days after the invoice date on average.

Setting up Net 15 in your ERP

Business Central

Due Date Calculation 15D

Xero

Bills due 15 day(s) after the invoice date

NetSuite

Term with Days Till Net Due 15

QuickBooks Online and Sage Intacct also store payment terms with a due rule. Whether an early-payment discount is applied to the bill automatically differs by product (Sage Intacct AP terms can carry one; Xero terms set due dates only), so check the bill's due date and amount after setting up a new term.

What it means

Net 15 is a net payment term. The full invoice amount is due 15 days after the invoice date, and there is no discount for paying early. The term is also written N15 or n/15. It does not count from the end of the month, and it does not give the buyer a choice between a discount date and a later net date. On a valid invoice, the only date the term produces is the due date.

The term describes when the invoice is due, not when the AP team should begin processing it. A clerk still needs to match the invoice to the purchase order and receipt, check the vendor, amount and invoice number, and place the payment in a run that reaches the vendor by the due date. A term of Net 15 shortens the window between invoice date and payment date, so late receipt, a mismatch, or a missing approval has less room to be fixed before the due date.

Read the term exactly as it appears on the invoice and compare it with the vendor master and purchase order. A vendor set to Net 15 in the master may send an invoice with different terms, and a purchase order may carry terms that differ from both. The invoice is the document being paid, but the vendor master controls what the ERP defaults to. When those two disagree, resolve the difference before the payment run rather than letting the system choose a date silently.

Working out the due date

For Net 15, add 15 calendar days to the invoice date. The invoice date is the date printed on the invoice, not the date the invoice arrived in the mailroom, the date it was scanned, or the date it was entered in the ERP. Those later dates are useful for tracking processing time, but they do not move the due date.

Three examples make the counting clear. An invoice dated 2026-01-15 is due 2026-01-30, a Friday, 15 days later. An invoice dated 2026-02-27 is due 2026-03-14, a Saturday, 15 days later. An invoice dated 2026-12-18 is due 2027-01-02, a Saturday, 15 days later. The last two due dates fall on a weekend. The term still produces those calendar dates; the payment run calendar and the organization's policy for weekend due dates determine when the payment is released.

Do not count from the received date. If an invoice dated 2026-01-15 is received on 2026-01-20, the due date remains 2026-01-30 under Net 15, not 2026-02-04. Counting from receipt gives the buyer extra days the term does not provide, and it can make the payment late. It can also hide a late invoice: if the due date has already passed when the invoice is entered, the AP team needs to see that immediately rather than resetting the date from receipt.

When the invoice date is missing or unclear, do not guess. Ask the vendor for a corrected invoice or confirm the date in writing. A due date built on an assumed invoice date is difficult to defend and easy to duplicate when the vendor sends a replacement.

Cash-flow effect

Net 15 is a short credit period. The buyer holds the invoice for 15 days after the invoice date before the full amount is due. For planning, the given figures use average days to pay of 15. At annual spend of 250,000, average owed under Net 15 is 10,274, which is 10,274 less than under Net 30. At annual spend of 1,000,000, average owed is 41,096, which is 41,096 less than under Net 30. At annual spend of 5,000,000, average owed is 205,479, which is 205,479 less than under Net 30.

The lower average balance is not a saving. It means the organization pays its suppliers sooner and therefore has less supplier credit outstanding. The cash has to come from somewhere else in the working-capital cycle. A controller comparing Net 15 with Net 30 should compare the shorter credit period with the organization's own cost of funds, not treat the lower payable balance as a gain.

Net 15 carries no early-payment discount, so there is no discount percentage, discount window, or cost-of-skipping-discount calculation attached to the term. If a vendor offers a discount on a different term, evaluate that offer separately and compare the discount with your own cost of funds. Do not apply a discount assumption to a straight Net 15 invoice.

Setting it up in your ERP

In QuickBooks Online, the Terms list holds terms that are due in a fixed number of days or due by a certain day of the month, and a term can carry an early-payment discount percentage and discount days. Set Net 15 as a fixed number of days after the invoice date, with no discount, and assign it to the vendor or use it on the transaction where the invoice terms call for it.

In Xero, payment terms can be set as a number of days after the invoice date, days after the end of the invoice month, a day of the following month, or a day of the current month. Net 15 is the first of those: days after the invoice date. Do not use the end-of-month or following-month options for Net 15, because those options produce a different due date.

In NetSuite, terms are stored as Term records with days until net due, a discount percentage and days until the discount expires. A Net 15 term needs 15 days until net due and no discount. Date-driven terms make a bill due on a set day of the month; those are not Net 15, even if the resulting date happens to be 15 days after a particular invoice date.

In Business Central, Payment Terms use date formulas for the due date and the discount date, for example 30D for 30 days or CM+30D for the end of the current month plus 30 days, plus a discount percentage. Net 15 needs a due-date formula that measures 15 days from the invoice date, not a month-end formula. In Sage Intacct, AP terms define when a bill is due and an optional early-payment discount; set the due date for 15 days after the invoice date and leave the discount blank. Whichever system you use, check the vendor default, the purchase order default and the invoice itself, and fix any term that was keyed as Net 30, 2/10 Net 30 or an end-of-month term.

Where these invoices go wrong

The most common Net 15 error is keying the wrong term. A vendor that should be Net 15 is left on Net 30, so the payment run releases it later than the invoice allows. The reverse also happens: a vendor on Net 30 is changed to Net 15 without a reason, and the organization pays early for no benefit. A related error is a term that looks similar but is not the same, such as 2/10 Net 30, being reduced to Net 15 in the vendor master. That removes the discount reminder and can cause the team to miss a discount window or take a discount after it has closed.

Counting from the received date instead of the invoice date is the second recurring mistake. It is easy to do when invoices arrive in a batch and the receipt date is the date everyone sees in the workflow queue. The result is a due date later than the term allows and a payment that is late by the time it is released. A dated invoice that arrives late should be flagged, not re-dated.

Duplicate payments often enter through the statement or the re-sent invoice. A vendor statement may list an invoice that is already paid, and the AP team pays the statement as well as the invoice. A vendor may re-send an invoice with a new date or a new reference, and the team pays the resend without checking the paid history. Under Net 15 the short window makes these errors less visible, because the first payment and the duplicate can land close together and the vendor may not flag the second one before the run.

Catch these problems before the payment run by matching vendor, invoice number, amount and invoice date against open and paid items. Review vendor statements against the paid ledger, not against the open invoice list alone. Check vendor credits before paying a statement, and look for a credit that was never applied. For terms, review the vendor master and any recurring bill templates for the wrong due-date logic. ERPSav connects to QuickBooks Online, Xero, NetSuite, Business Central and Sage Intacct, or takes a CSV export, and scans paid bills for duplicate payments, overpayments, missed early-payment discounts and unapplied vendor credits, then drafts the refund request to each vendor. That work reviews past payments for recovery; it does not replace the controls in the payment run.

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