Well, I'm only quoting the electricity guy's message to me. England moved from 240v to 230v for residential supplies a few years ago and everything still works just as well on 230 as it did on 240 but just used less electricity doing it. I'm guessing he's alluding to this. Most people here still think it's 240 because that's what they grew up with and they haven't noticed anything different plus the devices invariably say 220-240v on them
Actually I think we changed the specifications but not the supply! I think we were and still are on 240v and we fudged it by moving to EU standard 230v with a permitted upwards range of 10%.
I'm in London and my UPS says it's 250v.