A card acceptor ID (CAID) is a unique identifier assigned to a merchant by the acquiring bank or payment processor. It is used by card networks (Visa, Mastercard, etc.) and issuers to track merchant performance, route transactions, and analyze fraud or dispute trends. CAIDs are also used to enroll your business in chargeback prevention solutions such as Order Insight, Rapid Dispute Resolution (RDR), and Inform (reporting for fraud and chargeback notices).

CAIDs are typically tied to a single merchant account but may vary if you operate multiple accounts or business locations. It’s a back-end value not visible to customers but critical for processor-level operations.

If you manage multiple entities or sub-brands, it’s especially important to know which CAID is associated with which segment. AltoPay logs this value along with your transaction data so it’s easy to access during audits or dispute reviews. Having clear CAID visibility also supports compliance when working with multiple acquirers or service platforms.