(my brother works in ONS so may be able to give you some advice)
Basically all you need to do is phone up the Cencus hotline and tell them that you're a commercial address, not a household address. You could also mention to them that there is a flat above the business but you are not the resident or landlord.
#7357607, By Edge_san Small Business - Do I Have To Fill In A Census?
Edge_san 86 posts
Seen 46 minutes ago
Registered 10 years ago