MIR approved gas and electricity meters
Source: gov.uk (2025-11-06)

Approval process for gas and electricity meters under the Measuring Instruments Regulations 2016 (SI 2016/1153) (MIR).

Background

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 came into force 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), which was implemented into domestic law by the Measuring Instruments Regulations 2016 (SI 2016/1153) (MIR).

MID approved instruments will have passed specific conformity assessment procedures and have MID (CE) markings which allowed the instruments to be used in any EU member state. The aim of the directive was to create a single market in measuring instruments for the benefit of manufacturers and, ultimately, consumers across Europe. From 1 January 2021, MIR was amended so new electricity meter designs can have the UKCA Marking to be placed on the market in GB. Both CE and UKCA marked meters can continue to be placed on the market in GB.

MIR approval process

Under the MIR, gas and electricity meters are approved by UK Approved Bodies.

A list of UK Conformity Assessment Bodies, together with the instruments they have been designated to approve, is available on-line.

Access the list of UK CABs. (https://find-a-conformity-assessment-body.service.gov.uk/)

There are different conformity assessment options available for MIR approval and manufacturers are free to choose between them. For both gas and electricity meters the options are set out in Schedule 1B of the MIR and 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)
MIR electricity meter certification

Unlike meters approved under the Electricity Act 1989, certification is not recognised as a separate process under the MIR. MIR electricity meters are conformity assessed under the modules above. MIR electricity meters that have only Module B (i.e. type approval) are not approved for either primary (i.e. supplier-consumer) or secondary (i.e. landlord-tenant) billing applications.

Read guidance on electricity meter certification. (https://www.gov.uk/guidance/electricity-meter-certification)

MID and MIR markings

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 the year of manufacture (for example a meter manufactured in 2011 would have M11), and a four-digit code identifying the EU Notified Body that approved and verified the meter.

From 1 January 2021, new meter designs of electricity meters placed on the market in GB can have the UKCA mark and be approved against the requirements of MIR.

There is no list of MIR UKCA Marked meters. These can be identified with the UKCA mark and also have the metrology ‘M’ marking followed by the last two digits of the year of manufacture (e.g. M22).

If your meter does not display these markings, it is not MIR approved.

Read guidance on using the UKCA marking. (https://www.gov.uk/guidance/using-the-ukca-marking)

In-service testing

There are no prescribed certification periods for MIR 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 MIR.

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.

Read guidance on IST for gas and electricity meters. (https://www.gov.uk/guidance/in-service-testing-for-gas-and-electricity-meters)

The regulations

In the UK, the recast MID was implemented by the Measuring Instruments Regulations 2016 (http://www.legislation.gov.uk/uksi/2016/1153/contents) (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 (http://www.legislation.gov.uk/ukpga/1986/44/contents). 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 (http://www.legislation.gov.uk/ukpga/1989/29/contents). However, this does not apply if the error of measurement exceeds that prescribed in the regulations.

Since 30 October 2006, all new designs of gas and electricity meters that are within the scope of the MID must meet the essential requirements of the directive plus the instrument specific requirements detailed in Annex IV (MI-002) and Annex V (MI-003). Since 31 December 2020, the directive’s requirements became assimilated law and are now reflected in Schedules 1A and Schedules 1D or 1E of MIR respectively.

Meters approved under domestic law prior to 30 October 2006, and that are in-service before 30 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 regulations placed on the market after 30 October 2016 must be MIR approved.

Scope of MIR

The MIR 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 domestic law with the MIR, it was agreed to maintain the existing regulatory scope of the Gas Act 1986 (i.e. the MIR applies to gas meters up to a maximum flow rate of 1,600 cubic metres per hour at standard conditions of temperature and pressure).

Electricity meters

When the UK implemented the MID for electricity meters into domestic law with the MIR, it was agreed the MIR 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 MIR 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 (http://www.elexon.co.uk/).

MID type approval certificates

All type approval certificates issued by UK notified bodies under MID are no longer valid, but remain available as a matter of public record on the National Archives.
- Access legacy MID electricity meter type approval certificates (https://webarchive.nationalarchives.gov.uk/ukgwa/20220702073159/https://www.gov.uk/government/publications/electricity-meter-type-approval-certificates-annex-mi-003) – National Archives website
- Access legacy MID gas meter type approval certificates (https://webarchive.nationalarchives.gov.uk/ukgwa/20220702210134/https://www.gov.uk/government/publications/gas-meter-type-approval-certificates-annex-mi-002) – National Archives website
- Access legacy MID gas meter type approval certificates issued by NMO Certification Services. (https://www.gov.uk/guidance/weights-and-measures-legal-metrology-delivery#our-services)