On a commercial invoice, “Net 10th prox” means the full invoice amount is due on the 10th day of the month after the invoice was issued. An invoice dated anywhere in March is due April 10th. An invoice dated anywhere in July is due August 10th. The specific day the invoice was written does not affect the due date, only the month it belongs to.
The term is common in wholesale, retail, and distribution billing, where a single buyer may receive dozens or hundreds of invoices from the same vendor each month and needs one predictable payment date instead of a different deadline for every invoice.
What Each Part of the Phrase Means
Three words, three instructions.
Net means the full invoice amount is owed. No early payment discount is built in. That distinguishes it from a term like “2/10 Net 30,” where paying quickly earns a percentage off the bill.
10th is a fixed calendar day. It is not a countdown from the invoice date; it is a specific day of a specific month.
Prox is short for the Latin proximo, meaning “in the next month.” It pushes the due date into the month after the one the invoice was issued in.
Together, they create a single monthly collection point. Every invoice dated in a given calendar month shares the same due date: the 10th of the following month.
How to Calculate the Due Date
Find the calendar month printed on the invoice, then mark the 10th of the next month. The specific invoice date does not matter.
- Invoice dated January 3: due February 10th.
- Invoice dated January 15: due February 10th.
- Invoice dated January 31: due February 10th.
All three invoices land on the same due date because they share the same invoice month. This is the point where prox terms differ from a term like Net 30, under which each invoice starts its own countdown from the day it was issued. Under Net 30, the January 3rd invoice would be due February 2nd and the January 31st invoice would be due March 2nd. Under Net 10th prox, they meet on February 10th.
The tradeoff is uneven payment windows. That January 3rd invoice gives the buyer 38 days to pay. The January 31st invoice allows only 10 days. Invoices dated late in the month create the tightest turnarounds.
The Billing Cutoff That Changes the Math
Because late-month invoices can leave uncomfortably short payment windows, many vendor agreements add a billing cutoff, most commonly around the 25th of the month. Invoices dated after the cutoff are treated as if they belong to the next month’s billing cycle, which pushes the due date forward by an additional month.
With a 25th cutoff:
- Invoice dated January 20: falls before the cutoff. Due February 10th.
- Invoice dated January 28: falls after the cutoff. Treated as a February invoice. Due March 10th.
The cutoff is not automatic and it is not universal. It has to be spelled out in the contract or purchase order. If your vendor agreement simply says “Net 10th Prox” with no cutoff mentioned, the standard reading applies: every invoice dated in a given month is due on the 10th of the next month, even if that leaves only a few days to pay. Read the actual agreement before assuming a cutoff exists. Getting this wrong is one of the most common ways buyers pay late on prox terms without meaning to.
When the 10th Falls on a Weekend or Holiday
Occasionally the 10th lands on a Saturday, Sunday, or federal bank holiday. In most commercial agreements, when a fixed due date falls on a non-business day, payment made on the next business day is considered timely. A due date falling on Saturday would shift to Monday.
That is a default, not a guarantee. Some vendor agreements state that payment must be received by the due date regardless of weekends. Others build in an explicit grace period. If you are mailing a check, schedule it to arrive before the 10th whenever the calendar looks tight. ACH transfers and wires that clear on the next business day are the safest option when the 10th falls awkwardly.
Prox Terms With Early Payment Discounts
Not every prox term is a “net” term. Some vendors combine prox dating with an early payment discount. A term like “2/10th Prox, Net 30th” means the buyer earns a 2% discount by paying on or before the 10th of the following month, but owes the full undiscounted amount if payment arrives after the 10th and by the 30th.
On a $100,000 invoice, the 2% discount saves $2,000 for paying by the earlier prox date. Whether capturing that discount makes sense depends on your cost of capital: if short-term borrowing to pay early costs less than the discount saves, taking it pays off.
When a discount is paired with prox dating, read carefully to see whether both the discount window and the net window use the prox calendar, or whether one counts from the invoice date. The structure varies by vendor. Misreading it means either missing a discount you could have captured or paying late when you thought you were on time.
How Net 10th Prox Compares to Net 30 and EOM
Net 30 gives the buyer 30 calendar days from the invoice date to pay. Net 60 and Net 90 extend that to 60 or 90 days. These terms are easy to calculate but produce a different due date for every invoice.
EOM, or “End of Month,” dating works much like prox dating. Under EOM terms, the payment clock starts at the end of the invoice month rather than the invoice date. “Net 10 EOM” means payment is due 10 days after the end of the invoice month, which lands on the 10th of the following month. In practice, “Net 10 EOM” and “Net 10th Prox” produce the same due date. The wording differs by industry and region; the result is identical.
The real choice a vendor is making is between fixed-date terms (prox, EOM) and floating-date terms (Net 30, Net 60). Fixed-date terms consolidate payments into one predictable point in the month. Floating-date terms give the buyer a consistent number of days regardless of when the invoice was issued.
What Happens If You Pay Late
Missing a prox due date triggers the same consequences as missing any other payment deadline. The most immediate is a late payment fee, usually stated on the invoice or in the vendor agreement. Standard late fees on commercial invoices commonly run between 1% and 2% per month on the outstanding balance, though the specific rate depends on what the contract says and what state law allows.
Beyond the fee, repeated late payments erode the trade credit relationship. A vendor may shorten payment terms on future orders, require deposits or prepayment, reduce credit limits, or stop extending credit at all. For a business that relies on trade credit to manage working capital, losing favorable terms can cost more than the interest itself.
Federal agencies that pay vendors late owe mandatory interest under the Prompt Payment Act, at a rate set by the Treasury Department and published in the Federal Register.1Office of the Law Revision Counsel. 31 U.S. Code 3902 – Interest Penalties That statute does not cover private-sector contracts. For those, the contract itself should specify a late-payment interest rate. When the contract is silent, state law fills the gap, and default rates commonly fall between 5% and 12% annually.
Setting Up Prox Terms in Your Accounting System
Most accounting platforms support prox payment terms, but they rarely come preconfigured. You will need to create a custom payment term and define the day of the month (10th), the number of months forward (1), and, if your agreement includes one, a cutoff day. In QuickBooks, Sage, and similar platforms, this lives under payment terms setup in the vendor or accounts payable module.
Once configured, the system calculates due dates automatically on every invoice assigned that term. That removes the manual date math where late-month invoices are easiest to miscalculate. If your agreement has a billing cutoff, make sure the system reflects it. A system set for straight Net 10th prox with no cutoff will mark a January 28th invoice due on February 10th even if your contract actually pushes it to March 10th.
If you run regular payment cycles, scheduling the payment run for the 8th or 9th of each month gives you a buffer for weekends and processing delays while keeping payments comfortably ahead of the deadline.