It usually happens when someone pays with a credit or debit card. If the confirmation is not given in the app within a certain time limit, the bank rejects the

It usually happens when someone pays with a credit or debit card. If the confirmation is not given in the app within a certain time limit, the bank rejects the card transaction. Edit: to clarify, my comment is about the UK, and it does not happen with most card transactions; "usually" here refers instead to card transactions being the usual trigger (in my experience) for this app-based authentication flow.