Tachographs are devices that record information about driving time, speed and distance. This information is used to monitor compliance with drivers' hours rules.
If you drive a bus, coach, lorry or other vehicle under the European Union (EU) drivers' hours rules or the European Agreement concerning the work of Crew of Vehicles Engaged in International Road Transport (AETR) drivers' hours rules, you will almost always need to use a tachograph. However, if the vehicle you drive is exempt from the EU drivers' hours rules, you will not have to use a tachograph, even if one has been fitted to the vehicle.
There are two types of tachograph: analogue and digital. Analogue tachographs record the driver's periods of duty on a wax-coated paper disc, while digital tachographs store the information on an electronic 'smart card'.
By law, all commercial vehicles first registered on or after 1 May 2006 must be fitted with digital tachographs. However, you can continue to operate an analogue tachograph in an vehicle registered before that date.