A thousand pound Saving doesn’t interest you... ok?
It’s a “downgrade” in specification and I seriously doubt your insurer will care....
Call your insurer up and ask them as no matter what anyone says on here you won’t know until you ask your insurer.
In the context of this thread ie incorrect number of seats, specifically, 5 in van v’s 6 on the V5, the reduction in premium doesn't interest me as it would be negligible. I’m concerned for the OP and any potential grief should they have a claim.
Regarding my van, yes I was pleased with the £1k reduction losing a seat but the primary driver was SWMBO having a comfy captains chair that didn’t aggravate her back.