Vehicle registration plates of Europe

A vehicle registration plate, also known as a number plate (British English), license plate or licence plate (American English and Canadian English respectively), is a metal or plastic plate or plates attached to a motor vehicle or trailer for official identification purposes. The registration identifier is a numeric or alphanumeric code that uniquely identifies the vehicle within the issuing authority's database. In Europe most countries have adopted a format for number plates that satisfies the requirements in the Vienna Convention on Road Traffic, which states that cross-border vehicles must display a distinguishing code for the country of registration on the rear of the vehicle. This sign may be an oval sticker placed separately from the registration plate, or may be incorporated into the vehicle registration plate. When the distinguishing sign is incorporated into the registration plate, it must also appear on the front registration plate of the vehicle, and may be supplemented with the flag or emblem of the national state, or the emblem of the regional economic integration organisation to which the country belongs. An example of such format is the common EU format, with the EU flag above the country code issued in EU member states.
Format.
The vast majority of European countries issue registration plates that are:
This is one of the basic standard sizes worldwide.
The others are:
Some European countries use registration plates in other formats: 
European Union.
The common EU format of having a blue section on the extreme left with EU circle of stars and the country code was introduced by Council Regulation (EC) No 2411/98 of 3 November 1998 and entered into force on the 11 November 1998. It was based on a model registration plate which three member states had already introduced: Ireland (1991), Portugal (1992) and Germany (1994). Luxembourg plates had displayed the EU flag on the left since 1988. Vehicles with EU number plates do not need to display the white oval international vehicle registration code while within the European Economic Area, or in countries party to the Vienna Convention on Road Traffic (except if the plate is issued in Cyprus, Ireland, Malta and Spain). 
Other countries.
Several non-EU European states have implemented formats similar to the EU format, with national flags or symbols in place of the circle of stars. Vehicles with such number plates, issued in countries party to the Vienna Convention on Road Traffic, do not need to display the white oval international vehicle registration code while within countries signatory to the Vienna Convention on Road Traffic.
Common letter and digit systems between countries.
Several countries have made efforts to avoid duplicating registration numbers used by other countries. This is not completely successful and there are occasional difficulties in connection with parking fines and automatic speed cameras.
Differing numbering systems.
Individual European countries use differing numbering schemes and text fonts:
Cross-border traffic.
According to the Vienna Convention on Road Traffic, vehicles in cross-border traffic are obliged to display a distinguishing sign of the country of registration on the rear of the vehicle. This sign may either be placed separately from the registration plate or, after the convention was amended in 2006, may be incorporated into the vehicle registration plate. One of the main benefits of the convention for motorists is the obligation on signatory countries to recognise the legality of vehicles from other signatory countries. The following requirements must be met when driving outside the country of registration:
The common EU format of having a blue section on the extreme left with EU circle of stars and the country code was introduced by Council Regulation (EC) No 2411/98 of 3 November 1998 and entered into force on the 11 November 1998. According to Article 3 of the regulation shall member states that require vehicles registered in another member state to display a distinguishing registration sign also recognize distinguishing signs issued in accordance with the regulation (the common EU format). After the amendment of the Vienna Convention on Road Traffic in 2006, registration plates issued in the common EU format also satisfies the requirements of the named convention and hence is also valid in all countries party to the Vienna Convention on Road Traffic (if the issuing country is party to the convention). 
After Brexit, The European Commission has confirmed that after Brexit, British cars with number plates with the distinguishing sign incorporated do not need a separate sign when driving in EU countries party to the Vienna Convention on Road Traffic. If the number plate does not include the distinguishing sign, or if the vehicle is driven in an EU country not party to the Vienna Convention, a separate sign has to be displayed at the rear of the vehicle. All EU countries except Cyprus, Ireland, Malta and Spain are party to the convention. 
Some European countries are not party to the Vienna Convention on Road Traffic. Ireland, Cyprus, Iceland and Malta are examples of non-signatory countries. Those who have not ratified the convention may be parties to the older 1949 Geneva Convention on Road Traffic, which is the case of the aforementioned countries. According to the Geneva convention, a distinguishing sign of the country of registration must be displayed on the rear of the vehicle. This sign must be placed separately from the registration plate and may not be incorporated into the vehicle registration plate. The letters shall be in black on a white background having the shape of an ellipse with the major axis horizontal.
List.
Vehicle registration plates of each country are described in the following table:
Motorcycle plates are used for motorcycles and vehicles where mounting space is an issue, such as taxis which display their registration plate beside the registration plate, and vehicles imported from countries where the mounting space was not originally designed to take European-sized plates (e.g. USA).
Timeline.
 European countries
 Dependencies and disputed territories