I just popped onto censusNI page and yes they are asking for an access code so it can’t be started yet (leaving more time for people to read the ‘guidance’?)
Leaflet throught door only mentions 21 March, and on the web page the ‘Contact us’ won’t be open until 1st March.
In a previous life I had contact with lots of govt sorts and the prevailing attitude was “Better to ask for forgiveness than permission”
Not even ‘easier’ but ‘better’.
They know what they’re at.
Incidentally, the phrase is one I’ve also noticed to be v common amongst abusive persons who consider consent and mutual respect to be a waste of their time.