Exactly what information does a merchant get via Apple Pay when paying in person at a point-of-sale device?

Apple's [Apple Pay security and privacy overview](https://support.apple.com/en-us/HT203027) states (emphasis added): > # When you use Apple Pay in stores > > When you use Apple Pay in stores that accept contactless payments, Apple Pay uses Near Field Communication (NFC) technology between your device and the payment terminal. NFC is an industry-standard, contactless technology that’s designed to work only across short distances. If your iPhone is on and detects an NFC field, it will present you with your default card. To send your payment information, you must authenticate using Face ID, Touch ID, or your passcode (except when you use Express Mode with a payment or transit card). With Face ID or with Apple Watch, you must double-click the side button when the device is unlocked to activate your default card for payment. > > **After you authenticate your transaction, the Secure Element provides your Device Account Number and a transaction-specific dynamic security code to the store’s point of sale terminal along with additional information needed to complete the transaction.** Again, neither Apple nor your device sends your actual payment card number. Before they approve the payment, your bank, card issuer, or payment network can verify your payment information by checking the dynamic security code to make sure that it’s unique and tied to your device. I'm wondering exactly what information a merchant has access when using Apple Pay in person. The bolded sentence seems to contain the relevant information, but there are two problems: - "additional information needed to complete the transaction" could mean literally anything - This sentence covers what's transferred directly from the watch/phone to the point of sale device, but doesn't preclude other information being sent by Apple's servers or by the bank's servers as part of the protocol Does anyone know - and ideally have a citation for - what this "additional information" is, and whether more information is provided out-of-band? I'm primarily interested in the USA; if any details are country-specific, the USA answer is the one I'm looking for.