Why don’t retailers take payments from your account straight away?

[Jackcrwhitney (Jack)]

This Monzo article explains how they work:

​​How do card payments work?

I asked a similar question a few months ago and got this answer:

Refunds getting faster?

So my understanding is that it’s cheaper for merchants to batch process every few days. There may be other reasons that I’m unaware of!

Like you, I thought today in 2018 things would have been more instant!