The Short Answer: An Advance on Future Sales
A merchant cash advance (MCA) is not a loan. It's a form of business financing where a company provides a lump sum of cash to a business in exchange for a percentage of its future sales. In essence, the business is selling a portion of its future revenue at a discount to get cash immediately.
Imagine a restaurant owner's main oven breaks down mid-week. They need cash immediately for a repair to avoid shutting down for the weekend, but they lack the time or credit history for a traditional bank loan. An MCA provider could offer them a lump sum in a day or two. In exchange, the provider would take a set percentage of the restaurant's daily card sales until they have collected the initial amount plus a significant fee. On a busy Friday, the repayment is larger; on a slow Monday, it's smaller.
This structure is the key to understanding MCAs. Because they are legally defined as a commercial transaction (a purchase of future receivables) rather than a loan, they are not bound by many of the state and federal laws that cap interest rates on loans. This legal distinction allows them to be incredibly fast and accessible but also makes them one of the most expensive forms of business financing available.