What retail store doesn't have price tags on their items?

The point they’re making is that if there is a system failure which makes card payment unavailable, the failure could also have taken out the cash register entirely. And because most products only have a bar code on them which has to be scanned to get the price, it’s possible that the store can’t sell anything (unless they want to look up the price of every item at the shelf).

The interesting thing is that it was only the last mile of the payment processing that has failed whereas the core payment processing (payment networks) and intermediate layers (acquirers and mobile wallet infrastructure) have held up.

Reports about failing Apple/Google Pay actually pertained to the POS terminals the payment terminals are connected to, and not the payment infrastructure itself.

Another interesting takeaway is that we used to have an extra layer of redundancy available at the last mile of the payment processing: slip machines. They were a workaround and a fallback for exactly this kind of problem where the payment could not be processed electronically, a card payment slip would be taken, and the payment would be later processed manually.

However, with the uptake and the scale of electronic payments, card payment slips are no longer a thing mostly due to fraud related issues, plus the inconvenience of having to keep such a large contraption under the till. Even where still available, it may no longer be possible to use it as more and more debit (in particular) and even credit cards do not emboss the card details on the plastic/metal anymore.

To this point, I have shopped in grocery stores during power outages. The checkout terminals usually have battery backup and a local copy of the current prices to enable processing cash transactions.

Yeah. I've (rarely) been able to pay for an item without a price sticker in cash when credit card transactions were down.

Most, in large stores/chains. I'm not sure any of the large US stores I shop in have a price tag on the item any longer.

> I'm not sure any of the large US stores I shop in have a price tag on the item any longer.

But it’s in the shelf surely? Probably on an e-ink display.

But what good does that do at the checkout if computer systems are down? And no supermarket I frequent has eink displays on the aisles.

Besides which the central shelf label server is probably also down.

And do you expect the cashier to walk to the shelf for every single item in order to look up prices?