Fitting of or modification to: LVV certification is not required provided that:
the seat is either an OE seat from another vehicle, or similar to the OE seat and of a
known and reputable aftermarket brand, and
- the seat is fitted to unmodified OE seat anchorages, and
- the anchorage or operation of seatbelts is not affected, and
- the relationship between seat, seat occupant, and location of the seatbelt
anchorages is not affected, and
- the vehicle is not fitted with airbags in that seating position.
(Note that LVV certification is not required where the only modification is the removal of
seats and/or seatbelt anchorages. However, a class change and a new load rating may be
required in some cases.)
I suggest you check the legal issues first