Users access their passes in the Wallet app. For Apple Wallet users, Passes can display on the lock screen at the right time, like when the user reaches the airport or walks into a store.
Near Field Communication
Passes can work with Near Field Communication (NFC) readers for contactless redemption. Users hold their devices near a reader with contactless symbol to use a pass, with no need for a barcode. If you are developing an NFC-enabled you'll need to request an NFC certificate direct from Apple (approval can take some time). In addition to the NFC certificate there are a number of strict requirements before you can implement NFC passes.
Passes can contain barcodes that are scanned in order to obtain information stored in the pass. Wallet supports barcodes using QR, Aztec, PDF417 and Code128 formats. Wallet optimizes the presentation of passes in order to facilitate a successful scan. For example, the screen's orientation locks to portrait and the backlight is temporarily boosted to the brightest setting. However, it's still important to test your passes with the hardware you expect to use for scanning. An optical scanner works between for scanning a smartphone screen than a laser scanner.
If you are not integrating with scanning hardware, you can use the PassKit PassReader app to scan your passes.
For coupons, a user can tap on a link of the pass to redeem the coupon. We call this Customer Initiated Redemption (CIR).
Passes can also display text below the barcode to show the user's membership number or account number in case scanning is unavailable.