My understanding was that Google doesn't store your CVV anywhere, which is why you need to enter it every time. When you do so, it attempts to charge you zero u

My understanding was that Google doesn't store your CVV anywhere, which is why you need to enter it every time. When you do so, it attempts to charge you zero units of your preferred currency (or perhaps it gives you zero, not sure) and if the transaction succeeds it accepts the CVV as valid.