Insurer, and Vehicle Excise Duty (VED) / licence data, are shared by the relevant authorities including the Police and this forms an integral part of the mechanism of CIE. All UK registered vehicles, including those that are exempt from VED (for example, Historic Vehicles and cars with low or zero emissions) are subject to the VED taxation application process. Part of this is a check on the vehicle's insurance. A physical receipt for the payment of VED was issued by way of a paper disc which, prior to 1 October 2014, meant that all motorists in the UK were required to prominently display the tax disc on their vehicle when it was kept or driven on public roads. This helped to ensure that most people had adequate insurance on their vehicles because insurance cover was required to purchase a disc, although the insurance must merely have been valid at the time of purchase and not necessarily for the life of the tax disc. To address the problems that arise where a vehicle's insurance was subsequently cancelled but the tax disc remained in force and displayed on the vehicle and the vehicle then used without insurance, the CIE regulations are now able to be applied as the Driver & Vehicle Licence Authority (DVLA) and the MID databases are shared in real-time meaning that a taxed but uninsured vehicle is easily detectable by both authorities and Traffic Police. From 1 October 2014, it is no longer a legal requirement to display a vehicle excise licence (tax disc) on a vehicle. This has come about because the whole VED process can now be administered electronically and alongside the MID, doing away with the expense, to the UK Government, of issuing paper discs.
If the younger driver is covering his own costs, it might be cheaper for him to take out his own policy but include one of the older, lower risk drivers from the household as a named driver (as long as the older drive will use the car). However, if the older driver is footing the bill for both policies, multi-car insurance may still work out cheaper.