The maximum number of people (inc. driver) will be the number of seats stated on your registration document, this must tally with what you tell your insurance company when the policy starts. In other words, a series 3 landy (for example) will probably state '3 seats', even though there's room in the back for half a dozen passengers. A 5 seater Discovery (for example) carrying 7 people and involved in an accident would not be insured as the insurance has been invalidated by the extra 2 passengers.
Nigel.
What happens if (Like on a hell of alot of Series and Defenders) the number of people is not documented on the V5.....?