Trade credit is a common way for businesses to buy goods without paying immediately. Small businesses use trade credit a lot, about 20% of their debts. They can pay right away for a discount, wait and pay interest, or pay late and risk extra charges. Researchers made a model to understand why businesses use trade credit. They found that businesses use trade credit because they need it for managing cash and because they can't get enough credit from banks. The model also shows a connection between trade credit use and not getting enough credit from banks.