About MID Compliance for Utility Meters

Prior to October 2006, gas and electricity meters were placed on the market in accordance with the requirements of the Gas Act 1986 and the Electricity Act 1989. In October 2006, the European Measuring Instruments Directive (MID) 2004/22/EC was implemented to harmonise the requirements of 10 different measuring instrument types, including gas and active electrical energy meters. In April 2016 the original MID was replaced by the ‘recast’ MID (2014/32/EU) implemented by The Measuring Instruments Regulations SI 2016/1153.

MID approved instruments will have passed specific conformity assessment procedures and have MID markings which allow the instruments to be used in any EU member state. The aim of the directive is to create a single market in measuring instruments for the benefit of manufacturers and, ultimately, consumers across Europe.

MID approval process

Under the MID, gas and electricity meters are approved by notified bodies, designated by member states. Manufacturers can obtain approvals from any notified body in any EU member state.

list of notified bodies, together with the instruments they have been designated to approve, is available on-line.

There are a number of different conformity assessment options available for MID approval and manufacturers are free to choose between these. For both gas and electricity meters the options are:

  • B+D (i.e. type examination and quality assurance of the production process)
  • B+F (i.e. type examination and product verification)
  • H1 (i.e. full quality assurance plus design examination)

Further information can be found on the European Commission website.

MID electricity meter certification

Unlike meters approved under GB national legislation, certification is not recognised as a separate process under the MID. MID electricity meters are either approved and certified (Annex B+D, Annex B+F or Annex H1) or they are not. MID electricity meters that have only Annex B (i.e. type approval) are not approved for either primary (i.e. supplier-consumer) or secondary (i.e. landlord-tenant) billing applications.

MID markings

There is no statutory list of MID approved gas meters or electricity meters (ie the equivalent of Schedule 4 although the Office for Product Safety and Standards (OPSS) publishes approval certificates issued by notified bodies designated in the UK.

MID approved gas and electricity meters can be identified by their specific markings, as required under the directive. These consist of the CE marking, the MID marking which is made up of the letter ‘M’ and then the year of manufacture (for example a meter manufactured in 2011 would have M11), and a four-digit code identifying the notified body that approved and verified the meter. If your meter does not display these markings, it is not MID approved

Type approval certificates

Access copies of:

Gas and electricity meter MID type approval certificates, issued by SGS United Kingdom Limited, BSI and TUV SUD BABT

Gas meter MID type approval certificates, issued by NMO Certification Services

In-service testing

There are no prescribed certification periods for MID approved meters so OPSS, in consultation with the industry, has developed In-Service Testing (IST) procedures for monitoring the performance of gas and electricity meters approved under the MID.

These procedures enable suppliers and asset owners to demonstrate they are fulfilling their statutory obligation to keep meter populations in proper order for correctly registering the quantities of gas and electricity consumed.

The regulations

In the UK, the MID is implemented by:

The Measuring Instruments Regulations (SI 2016-1153)

Gas meters put into use in accordance with these regulations are deemed to have been stamped and therefore meet the requirements of the Gas Act 1986. However this does not apply if the error of measurement exceeds that prescribed in the regulations.

Electricity meters put into use in accordance with these regulations are deemed to be of an approved pattern or construction, installed in an approved manner, and also certified; and therefore meet the requirements of the Electricity Act 1989. However, this does not apply if the error of measurement exceeds that prescribed in the regulations.

Since 30th October 2006 all new designs of gas and electricity meters that are within the scope of the directive must meet the essential requirements of the directive plus the instrument specific requirements detailed in Annex IV (MI-002) and Annex V (MI-003) of 2014/32/EU respectively.

Meters approved under GB national legislation prior to 30th October 2006, and that are in-service before the 30th October 2016, can continue in-service for as long as they meet the requirements under the Gas Act 1986 and the Electricity Act 1989. All meters, within the scope of the directive, placed on the market after 30th October 2016 must be MID approved.

Scope of MID

The MID is applicable to instruments for domestic, commercial and light industrial use although these terms are not defined.

Gas meters

When the UK implemented the MID for gas meters into national legislation, it was agreed to maintain the existing regulatory scope of the Gas Act 1986 (i.e. the MID applies to gas meters up to a maximum flow rate of 1,600 cubic meters per hour at standard conditions of temperature and pressure).

Electricity meters

When the UK implemented the MID for electricity meters into national legislation it was agreed the MID would not apply to meters where:

  • the maximum quantity of electricity supplied exceeds 100 kilowatts per hour (kW/hr); and
  • the meter provides measurement on a half-hourly basis

Electricity meters outside the scope of the MID will therefore continue to be approved by OPSS under national legislation as these must also meet the additional requirements of the Balancing and Settlement Code, administered by ELEXON.