On Thursday, 31 October 2019 20:38:50 UTC, Brian Gaff (Sofa) wrote:
What is the point of an isolator. Some time ago the tech guy round checking
for meter dates told me that most meters these days, from the one with the
blinking lights onwards, have had to have an always on supply, though I did
point out that in a power cut it could hardly have one!

Smart meters "phone home" on battery backup if there's a power cut. If only one meter phones home then it's treated as a tamper alert, and on the electrician's forum there are several reports of the DNO turning up quickly suspecting people are trying to fiddle the meter.

Owain