It started with a problem.
Trade credit — the practice of allowing a buyer to pay for goods after delivery — has existed in commerce for centuries. The formalization of specific terms (Net 30, Net 60, 2/10 Net 30) developed as business relationships became more standardized and less personal in the nineteenth and twentieth centuries. A 'Net 30' invoice means the buyer has 30 days from the invoice date to pay. A '2/10 Net 30' term offers a 2 percent discount if paid within 10 days. The specific notation became standard in American business, encoded into accounting software and expected by both buyers and sellers without extensive negotiation. The U.S. Small Business Administration documents how payment terms affect small business cash flow.
Historical sources below ↓Then something changed.
Net payment terms created a system of informal short-term credit across the business economy. A small manufacturer who sold on Net 30 extended credit to every customer for a month — capital that the manufacturer was not paid for during that period. Buyers, meanwhile, could use goods for 30 days before payment, effectively receiving short-term financing. The terms became so standard that departing from them — demanding payment on delivery, or offering Net 90 — carried a signal beyond the simple payment schedule. The management of accounts receivable and payable became a core function in companies of all sizes, driven by the conventions established through standard payment terms.
What a builder can learn.
Our interpretation: payment terms are a form of financing. When a business extends Net 30 credit to its customers, it is lending them money, whether it recognizes it that way or not. The cost of that credit — the interest on the capital tied up in unpaid invoices — is often invisible in small business accounting. For a business builder, understanding the true cash flow impact of the payment terms it offers and the terms it receives from suppliers is a foundational element of working capital management.
A door still open.
A hypothesis worth testing: if a small business calculated the total value of invoices currently unpaid beyond their due date, treated that amount as an interest-free loan it had extended to customers, and applied even a conservative cost of capital to it, would the implied annual cost justify the effort of improving payment collection?
How much of your current unpaid receivables represents money you have already earned but are effectively lending to customers at no charge?
Follow the evidence.
History is sourced below. Business lessons are editorial interpretations; future possibilities are questions to test, not predictions.
Prepared from primary-source histories. First edition: 25 Sept 2026.