A ‘green card’ is proof of motor insurance cover when driving abroad.
You should carry one for the vehicle you’re driving in the
EU (including Ireland), Andorra, Iceland, Liechtenstein, Norway, Serbia or Switzerland.
You will need to carry more than one green card if:
you have fleet or multi-car insurance - you’ll need a green card for each vehicle
your vehicle is towing a trailer - you’ll need one for the towing vehicle and one for the trailer or caravan (you need separate trailer insurance in some countries)
you have 2 policies covering the duration of your trip, for example, if your policy renews during the journey