Comment by samus

Those rely on a strong centralized government that can somehow penalize people for not keeping records up to date. Not necessarily by direct checks, but maybe via inconveniences caused by inaccuracies. They are probably using other data (aggregate statistics from health system, tax records, social services) to conduct cross checks.

A few years back in Austria there was a small scandal as a newly introduced government app to notify about changing residence was used by a member of parliament to declare they moved into the Parliament.