I'm still a little unsure about all the details in the UK, but I know that in at least some cases the process you describe isn't entirely accurate. I mostly use

I'm still a little unsure about all the details in the UK, but I know that in at least some cases the process you describe isn't entirely accurate. I mostly use a card from Monzo (https://monzo.com https://monzo.com) and I get a mobile push notification on every use – almost always within seconds of the transaction. This would seem to be a requirement for prepaid cards, at least, because otherwise overspends would be possible. I seem to remember that there is a whole class of cards which are coded as 'online only', meaning that transactions will fail unless they're taken online. The only place I've frequently seen this happen is on trains, where the mobile equipment is sometimes not capable of online transactions, or doesn't have a signal. Anyway, the point was that these transactions don't appear to be any slower than with any other card I've used, so I'm not totally sure that the speed really is down to not being online.