Delving into Google, it seems the legal instrument that covers our utility company's meters, is:-
“STATUTORY INSTRUMENTS
1998 No. 1566
ELECTRICITY The Meters (Certification) Regulations 1998 “
Its, SCHEDULE 4 [ from page 21 onwards, “CERTIFICATION PERIODS”, details the certification period against the many types of meters used.
LINK
To my way of thinking, once our meters fall outside their period of certification, then they are going to get changed out, which as I said earlier has occurred at our home, for this or some other reason.
The impressively long periods that many types remain in certification, probably accounts why many contributors here. have not our experience.