Net 30 payment terms give a buyer 30 calendar days from the invoice date to pay an invoice in full. It works as a short-term, interest-free loan from the vendor: the buyer receives the goods or services now and pays 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 business credit history.
When the 30-Day Clock Actually Starts
The countdown starts on a date named in the purchase order or contract. Usually that’s the invoice date, but some agreements tie it to the shipment date or the date services are completed. Read the contract before you assume.
Two common variations change the math. “Net 30 EOM” (end of month) starts the clock at the end of the month the invoice was issued, so an invoice sent May 11 under Net 30 EOM would be due June 30. “Net 30 Prox” (from the Latin proximo mense, meaning “the following month”) makes payment due on the 30th day of the month after the invoice date. Both variations simplify accounting for buyers who batch payments monthly. Which one applies depends entirely on the contract language.
Federal Contracts Follow a Different Rule
If you sell to a federal agency, the Prompt Payment Act, not your contract’s Net 30 language, sets the deadline. It requires federal agencies to pay contractors within 30 days of receiving a proper invoice when the contract does not specify a different date.2Office of the Law Revision Counsel. 31 USC Chapter 39 – Prompt Payment The agency is deemed to receive the invoice on the later of actual receipt or seven days after delivery. Late payments accrue interest at a Treasury-set rate, currently 4.125% per year for the first half of 2026.3Federal Register. Prompt Payment Interest Rate Contract Disputes Act The Act applies only to federal agency payments. Private business-to-business Net 30 arrangements are governed by whatever the contract says.
Early Payment Discounts and What They’re Really Worth
Many Net 30 invoices come with a discount for paying early. The most common notation is “2/10 Net 30”: pay within 10 days and take 2% off, otherwise the full amount is due by day 30. On a $10,000 invoice, paying within 10 days saves $200. Variations include 1/10 Net 30 and 3/10 Net 60. The percentages and windows are negotiable at the time you sign the contract.
Skipping a 2/10 Net 30 discount is more expensive than it looks. You’re paying 2% extra to hold cash an extra 20 days. Annualized, that’s roughly 36.7%, higher than most business lines of credit. The formula is:
(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 credit at a lower rate, borrowing to capture the discount usually saves money.
One trap to watch: the discount typically applies only when you pay the invoice in full within the window. A partial payment at day 10 does not usually earn a partial discount unless the contract says so explicitly. Negotiate that flexibility upfront if you expect to pay in installments.
What a Net 30 Invoice Should Include
The clock only starts cleanly when the invoice leaves no room to argue. 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 the buyer’s accounts payable team processes them 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 each charge.
- The buyer’s purchase order number, if one was issued, so approval isn’t held up by matching errors.
Confirming that the buyer received the invoice, whether through an email read receipt, a portal acknowledgment, or a delivery confirmation, protects you if the buyer later claims the clock never started.
Using Net 30 Accounts to Build Business Credit
One of the most valuable side effects of using Net 30 accounts is building a business credit profile. Business credit scores like 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.4Dun & Bradstreet. PAYDEX Score FAQs
Generating a PAYDEX score requires 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 payment data. When you’re opening Net 30 accounts specifically to build credit, ask the vendor in advance whether they report to Dun & Bradstreet, Experian Business, or Equifax Business. Office supply companies, shipping and packaging distributors, and industrial supply vendors are common starting points.
Reporting to Experian is free for the vendor but requires a membership application, monthly submission of encrypted data files covering all customer accounts, and a standardized format.5Experian. How to Report Data to Credit Bureaus as a Business Because reporting is voluntary and takes work, many smaller suppliers skip it. That’s why asking before you buy matters.
Tax Timing Depends on Your Accounting Method
How a Net 30 invoice hits your taxes depends on whether you use cash-basis or accrual-basis accounting.
Cash-Basis Businesses
Under the cash method, you report income when you actually receive payment, not when you send the invoice. A Net 30 invoice sent in December but paid in January is income in the year the payment arrives.6Internal Revenue Service. Publication 538 Accounting Periods and Methods For buyers on the cash method, the expense is deductible in the year you pay it.
Accrual-Basis Businesses
Under the accrual method, income is recognized when all events have occurred that fix your right to receive it and the amount can be determined with reasonable accuracy. The IRS calls this the “all-events test.” In practice, an accrual-method vendor reports the income when the invoice is issued (or when goods are delivered or services completed), regardless of when the 30-day payment actually arrives.6Internal Revenue Service. Publication 538 Accounting Periods and Methods That can create tax liability on income you haven’t yet collected.
Writing Off an Unpaid Invoice
If a Net 30 account goes permanently unpaid, vendors 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 you have to show reasonable collection efforts. You don’t need a court judgment, but you do need evidence the debt is genuinely worthless, not just overdue. The deduction is claimed in the year the debt becomes worthless, not the year the invoice was originally due.7Internal Revenue Service. Topic No. 453 Bad Debt Deduction
Protecting Yourself Before Extending Net 30
Offering Net 30 is real financial risk. You’re lending inventory or labor to every buyer who gets credit terms. A few tools reduce the exposure.
Credit Applications and Personal Guarantees
Most vendors require a credit application before extending terms, covering trade references, bank information, and often a personal guarantee. A personal guarantee makes the business owner individually liable for the company’s unpaid invoices. If the business folds or runs out of assets, you can pursue the owner’s personal assets. For a vendor, it’s often the most important line on the application, because it gives you someone to collect from even if the business entity becomes judgment-proof.
UCC-1 Financing Statements
When you sell goods on credit, filing a UCC-1 financing statement with the state creates a public record of your security interest in the goods or other collateral. If the buyer defaults or files bankruptcy, a filed UCC-1 puts you among secured creditors, toward the front of the line when a court distributes the debtor’s assets. Without one, you’re unsecured and stand behind secured creditors. A UCC-1 lasts five years; if you don’t file a continuation statement before it lapses, you lose secured status.
Trade Credit Insurance
For businesses extending large amounts of trade credit, trade credit insurance covers losses from buyer non-payment due to insolvency, extended default, or political risk such as currency restrictions or trade disruptions in international transactions. Cost varies with your industry, your customers’ creditworthiness, and coverage limits. It can be worth the premium when a single large buyer’s default could threaten your operations.
When the Buyer Doesn’t Pay
Once day 30 passes without payment, your options escalate.
Late Fees and Interest
Most Net 30 agreements include a late fee clause, usually a monthly percentage of the unpaid balance. State laws vary on the maximum rate you can charge on commercial invoices. Some states cap late-payment interest at specific annual rates; more than 30 states impose no statutory maximum on commercial contracts as long as the rate is stated in writing. Include a clear late fee provision in the original contract. Without one, collecting penalties becomes much harder.
Seller Remedies Under the UCC
For transactions involving goods, the Uniform Commercial Code gives an unpaid seller several remedies. You may withhold undelivered goods, stop goods in transit, resell the goods and recover damages, or sue for the full contract price if the goods have been accepted or can’t reasonably be resold.8Cornell Law Institute. Uniform Commercial Code 2-703 – Sellers Remedies in General You can also recover the price of accepted goods directly from the buyer.9Cornell Law Institute. Uniform Commercial Code 2-709 – Action for the Price UCC Article 2 applies to the sale of goods. Unpaid service invoices are governed by general contract law rather than the UCC.
Statute of Limitations
You don’t have unlimited time to sue on an unpaid invoice. Every state has a statute of limitations for breach of a written contract, typically three to ten years, with most states falling between three and six. The clock generally starts on the date payment was due, not the date you discovered it was missing. Once the statute expires, the debt is legally unenforceable even if the buyer clearly owes it. If you have a consistently delinquent account, talk to an attorney well before the deadline approaches.