No, Apple Pay is not available in Cambodia.

Apple Pay requires users to upload payment information to Apple Wallet and follow steps to verify it with their card issuer. Once uploaded, all information required for payment is linked to the app, so users do not need to physically handle the card when paying. Devices that support Apple Pay include iPhone 6 and later, Apple Watch, iPad, and MacBook.

Apple Pay works with any contactless payment system, not just Apple-specific terminals.
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Embedded near-field communication antennas allow Apple devices to communicate wirelessly with selected point-of-sale (POS) systems.

One of the main advantages of Apple Pay, besides its ease of use, is the increased level of security it offers. Apple Pay essentially creates a token within its infrastructure that replaces credit card information. Instead, the system creates what’s called a device account, which is encrypted and stored in the device’s Secure Element. After payment is made, it is the token used by the merchant to process the transaction, meaning they never have direct access to the card details.