There's no real definition of what is and what isn't a classic. For some insurers, it's more about how you use the car. For example, you can get a new MX-5 on a classic policy as long as you only use it for high days and holidays. For other cars, there's a 20/25/30 year period they need to clock up. As far as HMRC is concerned, then it's 40 years - that's when your car becomes a classic and is therefore exempt from paying VED.

Your Defender falls into the category of cars registered before March 1, 2001, which only has two categories. For cars not over 1549cc it's £160 a year; while over 1549cc is £265. Have a look here: www.gov.uk/vehicle-tax-rate-tables/rates-for-cars-...1