Affirm is a Buy Now, Pay Later (BNPL) and installment lending platform that lets consumers finance purchases at checkout — spreading payments over weeks or months — instead of using a credit card. Affirm charges no late fees and no deferred or compounding interest, which it positions as a key differentiator from traditional consumer credit. Affirm offers three main products: short-term Pay-in-X plans (typically 0% APR), longer-term 0% APR installment loans subsidized by merchants, and interest-bearing fixed simple-interest installment loans, which represent roughly 72% of GMV. Affirm operates as a two-sided network connecting consumers and merchants. Merchants integrate Affirm at checkout via API, and consumers can also access Affirm through its app or the Affirm Card, a Visa debit card enabling pay-now or pay-later on any purchase. Affirm earns revenue from merchant fees (MDR) on each transaction and interest income on loans it originates or purchases. Affirm funds its loan book not through deposits, but through warehouse facilities, ABS securitizations, and forward flow arrangements with institutional investors. Affirm underwrites every transaction individually using ML models trained on data from hundreds of millions of loans, which it argues drives superior approval rates and credit performance. Key enterprise merchant partnerships include Amazon, Shopify, and Walmart. Affirm is also expanding internationally, with a recent U.K. launch, and is embedding its financing into AI-driven commerce environments and digital wallets.