[philpem]

If they put the FSA "Scores on the Doors" (and local council) food standards ratings on, the act of looking up the address would tell them something was up.

"Address given is not registered as a restaurant or food outlet" (aka: they're not registered with the local council).

I've gotten into the habit of checking 'Scores, just because of the sheer number of poor quality food places on Deliveroo, Just Eat and so on.