You do have to be very careful what you tell insurance companies because everything goes on a database and nothing you say can be unsaid.
I had a problem a few years ago when I bought a Discovery. For years my only vehicle had been a van on commercial insurance. I had maximum NCB on the van but I'd have none on the 4x4 if I started again from scratch, so I asked my insurers (Adrian Flux) to add the Discovery as a second vehicle to my van insurance. We can't do that, they said, the Discovery isn't a commercial vehicle. But I use it for work I said. Even so, they said, it's not a van, so you'll have to put it on a commercial 4X4 policy. That was stupid money, over a grand. OK I said, scrap that. I'll just have to bite the bullet and start from scratch with zero NCB on a regular car policy. Give me your best price for social/domestic/private light goods.
We can't quote you PLG they said, because you've just told us you're using the vehicle for work. I said, then I won't use it for work. I'll stick to the van and keep the 4x4 for private use. But they wouldn't have it. Having told them I'd be using the Disco commercially, they'd classed it as a commercial vehicle and that's all they quote me for, at eye-watering rates. And everywhere I tried to insure it, it came back as a commercial vehicle. In the end I had to insure with Lancaster as a classic vehicle on a strict mileage limitation with no NCB accruing. It was a nightmare. Luckily I got fed up with the unreliability and footwells filling up with water every time it rained so I got shot of it after a couple of years.
Lesson learned. Be very careful what you tell the b*stards.