3 ms·

EMV (chip/contactless) credit cards are capable of working without an internet connection, including PIN or device-based verification. Transactions get stored/b

EMV (chip/contactless) credit cards are capable of working without an internet connection, including PIN or device-based verification. Transactions get stored/batched on the payment terminal until the connection is available again. EV chargers often still require internet, however, as payment is via app or their own RFID card/dongle. Putting credit card readers directly on the chargers is a relatively recent (and not yet universal) improvement. Another reason for internet is so that chargers can report their availability status. In-car navigation or charging apps can direct you to locations with available chargers, avoiding ones that are fully occupied or out of service.

modeless 6y ago
That may be theoretically possible but I very much doubt any retailers have that set up to work properly. Around here the gas stations still verify your ZIP code. Superchargers could also store transactions in theory but I doubt it actually works there either.
- Reason077 6y ago
  It certainly happens, very occasionally, here in the UK. You try to pay something with contactless but there's a long processing delay. The terminal will then time out and ask you to insert the card and enter PIN, and you will get something strange printed on the receipt like "CVM: offline PIN". You may then see the transaction pop up in your notifications a few hours later, or early the next morning. Also, some merchants do offline or semi-offline transactions as a matter of course. London Buses, for example, accept contactless payments via bank card. But the transaction must be processed very quickly and the mobile data connection is not entirely reliable - the bus could be in a tunnel or a coverage black spot. So what really happens is the transactions are batched and processed at the end of the day (this also allows them to do some post-processing for multiple-journey discounts, daily price caps, etc). Someone like London Buses isn't overly concerned about fraud because the transaction values are low. But they do have a way to blacklist cards numbers that are known to be bad.
fastball 6y ago
How do you verify there is enough balance in the account, etc? Pin+chip just verifies that the card is yours, not that the card can actually pay for anything. For example, you could use a VISA gift card with $0 balance to pay for things if you had a system that was accepting transactions while offline.
- Reason077 6y ago
  There's no way to verify the balance offline. But, generally speaking, the offline mode is only used if there's a network/connectivity failure, and there's generally no way for a fraudster to know in advance if that's going to happen. The acquirer (ie: the merchant's bank) accepts liability in the case of fraudulent transactions. There are limits on offline transaction values, and merchants that have high fraud risk may not allow it at all.

modeless 6y ago

That may be theoretically possible but I very much doubt any retailers have that set up to work properly. Around here the gas stations still verify your ZIP code. Superchargers could also store transactions in theory but I doubt it actually works there either.

Reason077 6y ago
It certainly happens, very occasionally, here in the UK. You try to pay something with contactless but there's a long processing delay. The terminal will then time out and ask you to insert the card and enter PIN, and you will get something strange printed on the receipt like "CVM: offline PIN". You may then see the transaction pop up in your notifications a few hours later, or early the next morning. Also, some merchants do offline or semi-offline transactions as a matter of course. London Buses, for example, accept contactless payments via bank card. But the transaction must be processed very quickly and the mobile data connection is not entirely reliable - the bus could be in a tunnel or a coverage black spot. So what really happens is the transactions are batched and processed at the end of the day (this also allows them to do some post-processing for multiple-journey discounts, daily price caps, etc). Someone like London Buses isn't overly concerned about fraud because the transaction values are low. But they do have a way to blacklist cards numbers that are known to be bad.

fastball 6y ago

How do you verify there is enough balance in the account, etc? Pin+chip just verifies that the card is yours, not that the card can actually pay for anything. For example, you could use a VISA gift card with $0 balance to pay for things if you had a system that was accepting transactions while offline.

Reason077 6y ago
There's no way to verify the balance offline. But, generally speaking, the offline mode is only used if there's a network/connectivity failure, and there's generally no way for a fraudster to know in advance if that's going to happen. The acquirer (ie: the merchant's bank) accepts liability in the case of fraudulent transactions. There are limits on offline transaction values, and merchants that have high fraud risk may not allow it at all.