What is a virtual account number and how is it different from my card account number?
When adding cards to Android Pay a virtual account number is created in place of your card account number. This number is used when you make a payment with Android Pay (or a refund of that payment), so that your card account number isn't shared with the merchant and won’t appear on the receipt. Each time you add your card to Android Pay, a new virtual account number is created.
If using Android Pay to obtain a refund, you may have to provide the last 4 digits of your virtual account number. You can find your virtual account number in the Android Pay app.
For payments processed through online merchants Android Pay will also use either your Virtual Account Number or another uniquely generated account number as a representation of your card to process the transaction.