You may be thinking of tokenization, which is a feature of some services such as Apple/Google Pay. This is where a “fake” account number—really a number that is scoped to eg a specific device or a specific merchant—is sent with the transaction. That then gets resolved to the real number somewhere down the processing pipeline closer to the card issuer. The benefit being if someone snoops this tokenized account number they won’t be able to use it thanks to the tight scoping.
The terminals really don't trust the POS systems.
You could reprogram a terminal in a bar in a few seconds on a Friday night. Wait for the weekends takings to clear into your merchant account, and then take off with the money. The way that it falls down though, is that you need a merchant account, and there’s a lot of KYC and due diligence to get through if you want to set one of those up (there are a lot of merchant initiated scams, and your bank doesn’t want to be on the hook for them).
That's the difficult part - since the acquiring bank is fully financially responsible if you do so (they'll compensate everyone else involved for the fraud chargebacks, no matter if they can recover it from you), they generally take quite stringent steps to fight merchant-initiated scams, and the simplest step is simply freezing the money for some time; 30 days is not uncommon but I have even seen 90 days if the merchant's profile is risky or if the incoming payment volume suddenly increases significantly - the bank is effectively treating any payments to the merchant as a line of credit or letter of guarantee until it's clear that those payments won't be fraudulent or charged back. So a merchant can quite realistically do some shenanigans with a reprogrammed terminal, but they won't be permitted to take off with a large amount of money from the merchant account until a sufficient amount of time will have passed for the first chargebacks or complaints of fraud to show up.
I think the main reason this never happens is because there’s a lot of easier and more profitable scams you can operate as a fraud-oriented merchant.
They started accepting signups a couple weeks before school started, and on the second day it was running, after several hundred signups (of ~$200 each iirc), apparently some security people from the bank showed up at the orientation office at the school basically just to confirm it was legit. (I don't remember if they suspended the account first or not)
I had built a few online store sites using merchant accounts by then, but nothing that went from zero to that volume so quickly; it was fascinating to see that check in action.
I wonder what volume it would take to trigger such scrutiny today, and what it would look like..
But in this hypothetical would there be chargebacks? People went to a bar. They consumed, and paid for it. As far as the costumers know it went all good.
The one who is harmed would be the pub. And presumably they would complain and soon.
I don’t doubt that the whole scheme would come to light quick, i’m just questioning the exact mechanism.
During that procedure the terminal unique ID is sent, and depending on your environment, if you have a stable outgoing IP the connection might be filtered on that as well (assuming you do that on site, not at a POS provider). Jumping through a bunch of hoops you might still be able to hook a POS on another merchant account, but once the issue is detected there would be enough info to reverse the transactions (doing that after capture could cost fees, but it’s still better than nothing).
Looking at the delays between the transactions being cleared and the money appearing in your bank account, even with the best timing you might not see a penny of all of that.
To be able to pull this off:
1. You need to register yourself as a merchant at an acquirer bank. Either directly or through intermediaries such as Stripe/Square etc.,
2. Go through reasonably stringent KYB (Know Your Business) process.
3. Do a few legitimate transactions so that everyone in the payment processing chain (acquiring bank, payment gateway etc., issuing bank, network (Visa/MasterCard)) begins to trust you.
4. Reconfigure the kiosk to use the above merchant account.
5. Pull out money from the acquiring bank before enough customers raise a charge-back and your your account is marked as fraudulent by someone/everyone in the payment processing chain.
These fly-by-night merchants are indeed created; especially at marketplaces such as EBay, Amazon. But to do it at a physical kiosk such as McDonalds' seems like a low ROI to me.
They have dedicated servers, so I'd expect McDonald's and other big chains to have them, too, which means that you couldn't send payments no anyone outside the mother company.
Yes they do. In fact, you can read the CC number from the chip without even knowing the PIN.