> Apparently a basic sanity check like "Are we already billing this card?" is not implemented at all
They most likely don’t store your actual card number.
They most likely don’t store your actual card number.
i'm in fantasy land, right?
Now that's currently only online, but they're releasing a point of sale product soon too. But even with that, you connect to their card reader and receive a token that you can use.
In fact Stripe and Braintree (and I'm sure others) have systems where the implementing service doesn't get the credit card number at all- the payment information is sent directly to the processor from the client and the implementing service only gets a vault token.