The Measuring Instruments Directive (MID) is a European directive (2004/22/EC) that harmonises the requirements of 10 different measuring instrument types, including gas, electricity, water, and heat meters.

 

MID approved meters, which include primary and secondary sub-meters, must satisfy specific conformity assessment procedures and have MID markings which allow the instruments to be used for fiscal billing purposes. Therefore clients can directly bill from the given meter readings.

 

Meters already installed, that were approved under UK National legislation prior to October 2006 may remain installed indefinitely, as long as they are measuring accurately. Any new meter manufactured and approved after October 2006 must be approved under the MID regulations.

 

It is a criminal offense to use a non-approved meter for fiscal billing purposes, carrying a potential fine of £1,000 per non-MID meter. A consumer is also within their rights to refuse payment on a non-MID meter.