The EMV standard has long supported an offline transaction flow. AFAIK it was the default almost everywhere in Finland circa 2011, contactless there was almost always instantaneous. Digging into why that was compared to the invariable wait when using contactless in the UK revealed this flow.
The card has a variety of risk counters on it that allow it to securely decide whether an offline transaction can proceed, at least some of which are also exposed to the terminal which can have its own separate policy. I imagine internally the banks and payment gateways have a huge variety of internal related tuneables.
The card has a variety of risk counters on it that allow it to securely decide whether an offline transaction can proceed, at least some of which are also exposed to the terminal which can have its own separate policy. I imagine internally the banks and payment gateways have a huge variety of internal related tuneables.