A "Proof of Purchase" is a document or receipt that verifies a customer has bought a product or service. This can include items like receipts, invoices, or warranty cards. It serves as evidence for returns, exchanges, or warranty claims, ensuring that the customer is eligible for these services. Retailers often require proof of purchase to process refunds or exchanges. It helps prevent fraud and ensures that customers receive the correct support for their purchases. Keeping proof of purchase is important for tracking expenses and managing warranties on items like electronics or appliances.