Instant, or fast, payments are credit transfers completed and settled within seconds or minutes. They have low costs, reduce payment risk, and have significantly replaced the use of cash, cards, or check and direct debit payments. We note the role played by regulators in promoting instant payments and identify instances of significant payment instrument substitution across 12 advanced and emerging market economies. This substitution reflects the realized demand for attributes offered by instant payments. As these attributes are quite similar to those for CBDC, the demand for retail CBDC (if issued) may be less compelling.