Essentially, you (the merchant) just write down their card number, and how much they paid you, and then later you send that list to your bank who sends it to the credit card network.
There is no big technical hurdle. There is a big social hurdle in convincing your bank and the network that you should be allowed to do this. Also the card number gets copied by a little pressing machine onto carbon paper or something like that, not just written down.
Being able to spend money you don't have is not a new thing, and poses no technical problems. American readers will know you can easily do that with a cheque. It's your responsibility not to do that, and that's one reason why the bank wants so much personal information to open an account, so they can send the police over to break your kneecaps.
Essentially, you (the merchant) just write down their card number, and how much they paid you, and then later you send that list to your bank who sends it to the credit card network.
There is no big technical hurdle. There is a big social hurdle in convincing your bank and the network that you should be allowed to do this. Also the card number gets copied by a little pressing machine onto carbon paper or something like that, not just written down.
Being able to spend money you don't have is not a new thing, and poses no technical problems. American readers will know you can easily do that with a cheque. It's your responsibility not to do that, and that's one reason why the bank wants so much personal information to open an account, so they can send the police over to break your kneecaps.