Net 30 is a trade credit arrangement that gives a buyer 30 calendar days from the invoice date to pay for goods or services in full. It works as a short-term, interest-free loan from the seller: the buyer receives what they ordered now and settles the bill later.1U.S. Small Business Administration. How Net 30 Accounts Help Conserve Business Cash Flow Businesses use it to manage cash flow, strengthen vendor relationships, and build a business credit history.
When the 30-Day Clock Starts
The 30 days usually start on the invoice date. Some contracts tie the clock to the shipment date or the date services were completed instead, so the exact trigger lives in the purchase order or contract language. Confirm it before you sign.
Two common variations change the math. “Net 30 EOM” (end of month) starts the countdown at the end of the month the invoice was issued, so an invoice sent on May 11 under Net 30 EOM would be due June 30. “Net 30 Prox” (short for the Latin proximo mense, meaning “the following month”) makes payment due on the 30th day of the month after the invoice date. Both tend to simplify accounting for buyers who batch payments on a monthly cycle.
Early Payment Discounts
Many vendors reward early payment. The most common notation is “2/10 Net 30,” meaning the buyer can deduct 2% from the invoice total by paying within 10 days; otherwise the full amount is due by day 30. On a $10,000 invoice, paying inside the discount window saves $200. Variations include 1/10 Net 30 and 3/10 Net 60, and the terms are negotiable when the contract is written.
Skipping that 2% discount is more expensive than it looks. You are effectively paying 2% to hold your cash for an extra 20 days, which annualizes to roughly 36.73% using the standard formula:
(Discount % ÷ (1 − Discount %)) × (360 ÷ (Full Payment Days − Discount Days))
For 2/10 Net 30: (0.02 ÷ 0.98) × (360 ÷ 20) ≈ 36.73%. If you have access to a line of credit at anything close to normal commercial rates, borrowing to capture the discount typically costs less than skipping it.
The early payment discount generally applies only when the full invoice is paid within the discount window. Paying half the balance by day 10 does not usually entitle you to take 2% off that half unless the contract explicitly allows partial-payment discounts. Negotiate that flexibility upfront if you expect to need it.
How Net 30 Compares to Other Terms
Net 30 is the most common trade credit window, but it sits on a spectrum. Shorter terms like Net 10 or Net 15 appear in industries where vendors need faster cash flow or margins are thin. Petroleum operates on windows of one or two days. On the longer end, Net 60 and Net 90 are common in manufacturing, heavy equipment, and other industries with extended production cycles or well-established buyer-vendor relationships.1U.S. Small Business Administration. How Net 30 Accounts Help Conserve Business Cash Flow
Longer terms directly affect a company’s Days Payable Outstanding (DPO), the average number of days it takes to pay bills. Moving from Net 30 to Net 60 doubles the time you hold cash, which frees working capital for other uses. For buyers, longer terms are almost always better; for vendors, they increase the risk of non-payment and tighten liquidity.
What Belongs on a Net 30 Invoice
A clean invoice removes ambiguity about when the clock started and reduces disputes. At a minimum, include:
- The invoice date, which anchors the 30-day countdown.
- The payment terms stated explicitly, such as “Net 30” or “2/10 Net 30,” so accounts payable staff can process the invoice correctly.
- A calculated due date as an actual calendar date, not just the terms.
- Line-item descriptions with quantities, unit prices, and totals so the buyer can verify the charge.
- The purchase order number, if the buyer issued one; referencing it speeds approval and avoids matching errors.
Larger companies often require invoices in Electronic Data Interchange (EDI) format, specifically the EDI 810 transaction set. The data is the same (invoice date, invoice number, PO reference, line items, total) but formatted to feed directly into the buyer’s accounting system.
Building Business Credit with Net 30 Accounts
One of the most valuable side effects of Net 30 accounts is building a business credit profile. Business credit scores, such as the Dun & Bradstreet PAYDEX, are calculated from how reliably you pay trade credit invoices relative to their terms. A PAYDEX score of 80, the benchmark considered “prompt,” means you consistently pay within terms. Scores above 80 indicate early payment; scores below 70 signal payments running 15 or more days late.2Dun & Bradstreet. PAYDEX Score FAQs
To generate a PAYDEX score, you need at least two suppliers reporting trade data and a minimum of three payment experiences on file. That usually takes 90 to 120 days from your first reported purchase. Not every vendor reports, so if you’re opening Net 30 accounts specifically to build credit, ask upfront whether the vendor reports to Dun & Bradstreet, Experian Business, or Equifax Business. Common starting points include office supply companies, shipping and packaging distributors, and industrial supply vendors.
Reporting to Experian, for example, is free for the vendor but requires a membership application, monthly submission of encrypted data files covering all customer accounts, and a standardized file format.3Experian. How to Report Data to Credit Bureaus as a Business Because reporting takes effort and is voluntary, many smaller suppliers simply don’t do it.
Tax Treatment of Net 30 Invoices
How Net 30 affects your taxes depends on whether your business uses cash-basis or accrual-basis accounting.
Cash-Basis Businesses
Under the cash method, you report income when payment actually arrives, not when the invoice is sent. A Net 30 invoice sent in December but paid in January counts as income in the year the payment arrives.4Internal Revenue Service. Publication 538 Accounting Periods and Methods For buyers on the cash method, the expense is deductible in the year it is paid.
Accrual-Basis Businesses
Under the accrual method, income is recognized when all events have occurred that fix the right to receive it and the amount can be determined with reasonable accuracy. The IRS calls this the “all-events test.” In practice, a vendor on the accrual method reports the income when the invoice is issued or the goods are delivered, regardless of when the 30-day payment actually arrives.4Internal Revenue Service. Publication 538 Accounting Periods and Methods That timing difference can create tax liability on income not yet collected.
Writing Off Unpaid Invoices
If a Net 30 account goes permanently unpaid, a vendor who previously reported the income may be able to claim a bad debt deduction. The amount must have been included in gross income in the current or a prior tax year, and the vendor must show reasonable collection efforts. A court judgment is not required, but there must be evidence the debt is genuinely worthless, not merely overdue. The deduction is claimed in the year the debt becomes worthless, not the year the invoice was originally due.5Internal Revenue Service. Topic No. 453 Bad Debt Deduction
When the Buyer Doesn’t Pay
Once day 30 passes without payment, the vendor’s options escalate in stages.
Late Fees and Interest
Most Net 30 agreements include a late fee clause, often stated as a monthly percentage of the unpaid balance. State laws vary: some cap late-payment interest on commercial invoices at specific annual rates, while more than 30 states impose no statutory maximum on commercial contracts as long as the rate is stated in writing. Without a clear late fee clause in the original contract, collecting penalties becomes much harder.
Seller Remedies Under the UCC
For transactions involving goods, the Uniform Commercial Code gives an unpaid seller several remedies. The seller may withhold any undelivered goods, stop goods in transit, resell the goods and recover damages, or sue for the full contract price when the goods have already been accepted or cannot reasonably be resold.6Cornell Law Institute. Uniform Commercial Code 2-703 – Sellers Remedies in General The seller can also recover the price of accepted goods directly from the buyer.7Cornell Law Institute. Uniform Commercial Code 2-709 – Action for the Price UCC Article 2 applies to the sale of goods only; unpaid service invoices are governed by general contract law.
Statute of Limitations
Vendors do not have unlimited time to sue. Every state has a statute of limitations for breach of a written contract, typically between three and ten years, with most states in the three-to-six-year range. The clock generally starts on the date the payment was due, not the date you discovered the shortfall. Once it expires, the debt becomes legally unenforceable even if the buyer clearly owes it.
A Note on Federal Contracts
Net 30 as described here is a private contract term, set by the parties. If you sell to a federal agency, a separate statute applies. The Prompt Payment Act requires federal agencies to pay contractors within 30 days of receiving a proper invoice when the contract does not specify a different date.8Office of the Law Revision Counsel. 31 USC Chapter 39 – Prompt Payment The agency is deemed to receive the invoice on the later of the actual receipt date or seven days after delivery. If the agency pays late, it owes interest at a rate set by the Treasury Department, currently 4.125% per year for the first half of 2026.9Federal Register. Prompt Payment Interest Rate Contract Disputes Act The Act does not reach private business-to-business transactions, which remain governed entirely by the contract itself.