The EU in its 'wisdom' has declared a full bike licence needed to drive this 'car'. This came in with implementation of the third European driving licence directive.
My understanding is this was grandfathered everywhere, so if you had a valid licence to drive one before the implementation, you should have one now (19th January 2013).
In the UK, one should get group A with note 79 added when one renews a full car licence with a test date pre 19/1/2013. And this should satisfy any other country in Europe.
Additionally, the UK adopted the derogation that allows anyone over 21 with a valid car licence, to drive a trike but this is not exportable and won't even cover one on a trip to France (say) from the UK.
That's how I recall the legislation, Martyn.
EU driving licence categories have been harmonised between member states, one of the advantages of being in the EU, so everyone should take a few minutes to check theirs. If you've renewed yours here in the UK then you should also check the new version has all the same entitlements as the one you sent off because it's been known for some to get 'mislaid'..
Harmonisation means that everyone's licence in the UK should look the same as member states, hence the authorities should be quite clued up about yours whilst they look at it.
The difference is, as Martyn has written, each country can have differing sub-clauses.
