I think its confined to places outside of major metropolitan areas, where the vast majority of money moves around.
If you have a credit card you don't need a bar tab.
If you have a credit card you don't need a bar tab.
That's the normal method in Britain -- your credit card is generally put in a little booklet behind the bar, so they can charge it if you forget at the end of the night¹. Alternatively, they may take a payment upfront -- for example, if a large group of teenagers have booked a private area of a nightclub and put £500 up for a tab. The drinks continue until the upfront money is spent.
I assume the situation is a little more relaxed for the regulars in a rural pub.
¹ They won't have your PIN, but they can still run the transaction -- though it's easier for the cardholder for dispute.
a tab is where you dont pay at all for an extended amount bof time, and settle afterwards. for example, you might settle monthly, or yearly. i do think this kind of tab doesn't happen very often.