The Merchant can use the Device Primary Account Number to process your return.
If the cashier needs your card details:
On the device that you used to buy the item, choose the card that you want to be refunded in Apple Pay.
On your iPhone, hold the device near the reader and authorise.
On your Apple Watch, double click the side button and hold the display of your Apple Watch within a few centimetres of the contactless reader. The store can use the Device Primary Account Number to process your return.
To find the DPAN on your iPhone or iPad:
Open the Settings app.
Scroll down to Wallet & Apple Pay.
Tap the card.
For Apple Watch:
Open the Apple Watch app on your iPhone.
Go to the My Watch tab & tap Wallet & Apple Pay.
Tap your card.
If the cashier needs your card details:
On the device that you used to buy the item, choose the card that you want to be refunded in Apple Pay.
On your iPhone, hold the device near the reader and authorize.
On your Apple Watch, double click the side button and hold the display of your Apple Watch within a few centimetres of the contactless reader.