MID - Directive 2014/32/EU

What MID is and why it matters

The Measuring Instruments Directive (MID) — formally Directive 2014/32/EU on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments — is the EU’s framework law for instruments that measure quantities used in trade, official and public-interest settings. If your product measures water, gas, electricity, heat, distance, volume or weight and the reading forms the basis for a payment, a tax, a fine or a regulated decision, MID almost certainly governs how you may place it on the market.

MID matters because measurement is trust. When a consumer pays for the litres of fuel shown on a pump, the kilowatt-hours on an electricity meter, or the fare on a taximeter, they rely on the instrument being accurate and tamper-resistant. MID sets harmonised essential requirements for that accuracy, durability and protection against fraud, so that an instrument lawfully placed on the market in one Member State can circulate across the Union without facing different national metrology rules. It is part of the EU’s New Legislative Framework, sharing its structure of essential requirements, conformity assessment modules, notified bodies and CE marking with sister directives.

📄 Official text: Directive 2014/32/EU on measuring instruments — on EUR-Lex →

Who MID applies to

MID applies across the economic operators in the supply chain, with duties scaling by role:

Manufacturers — anyone who makes a measuring instrument, or has it made and markets it under their own name or trademark. They carry the heaviest obligations: meeting the essential requirements, choosing and completing the conformity assessment, drawing up technical documentation and the EU declaration of conformity, and applying the markings.
Authorised representatives — operators appointed in writing by a manufacturer to perform defined tasks on their behalf within the Union.
Importers — businesses placing instruments from outside the EU on the Union market. They must verify the manufacturer has carried out the correct conformity assessment, that documentation exists and that the markings are present, and must add their own identification.
Distributors — operators further down the chain who must act with due care, check that the CE and supplementary metrology markings and documents are present, and not make available instruments they know or should presume to be non-compliant.

MID covers instruments used for measuring functions in the public interest, public health, public safety, public order, protection of the environment, levying of taxes and duties, fair trading and the protection of consumers — in short, regulated and legal-for-trade measurement rather than purely industrial or private use.

Instrument categories covered

MID does not apply to every measuring device; it covers ten defined instrument categories, each with its own instrument-specific annex of detailed requirements:

Water meters — for clean cold or heated water in residential, commercial and light-industrial use.
Gas meters and volume conversion devices.
Active electrical energy meters.
Thermal energy (heat) meters.
Measuring systems for the continuous and dynamic measurement of quantities of liquids other than water — for example fuel dispensers and road-tanker metering systems.
Automatic weighing instruments — such as automatic catchweighers, gravimetric filling instruments, totalising hoppers and rail-weighbridges.
Taximeters.
Material measures — including material measures of length and capacity serving measures.
Dimensional measuring instruments.
Exhaust-gas analysers.

Each instrument type combines the general essential requirements in the main annex with the specific annex for that category. Note that non-automatic weighing instruments are regulated separately under their own directive rather than under MID.

Core requirements

Essential requirements: accuracy, durability and protection

At the heart of MID are essential requirements that an instrument must meet across the rated operating conditions and through reasonable disturbances and electromagnetic environments. Instruments must hold their accuracy within defined maximum permissible errors, resist the influences they will encounter in service, and offer durability so they keep performing over time. They must also be protected against corruption and unauthorised intervention — features that resist tampering, fraud and accidental misreading. Information accompanying the instrument, and the indication of the result, must be clear and unambiguous so the party relying on the measurement can read it correctly.

Conformity assessment via modules

MID uses the New Legislative Framework’s modular approach. For each instrument category the relevant annex lists which conformity assessment modules the manufacturer may choose from — combinations such as type examination (Module B) followed by conformity to type based on quality assurance or product verification (Modules D, F and others), or full quality assurance (Module H1). Most modules require the involvement of a notified body — an independent conformity assessment body designated by a Member State and listed in the EU’s NANDO database — because legal metrology generally does not permit pure self-declaration. The manufacturer selects an authorised module path, has the body perform the assessment, and on that basis declares conformity.

Technical documentation and the EU declaration of conformity

The manufacturer must compile technical documentation that demonstrates how the instrument meets the essential requirements — design, manufacture and operation, test results and the reasoning linking them to the requirements. They must then draw up an EU declaration of conformity stating that the essential requirements are met, and keep both the documentation and the declaration available for market surveillance authorities for the retention period set by the Directive. Where harmonised standards or normative documents have been applied, conformity with them gives a presumption of conformity with the corresponding essential requirements.

CE marking plus the supplementary metrology marking

A compliant instrument carries the CE marking together with the supplementary metrology marking, which is specific to MID: the capital letter “M” followed by the last two digits of the year it was affixed, surrounded by a rectangle. The supplementary metrology marking is placed immediately after the CE marking. Where a notified body is involved in the production-control phase, its identification number follows the markings. The markings must be affixed visibly, legibly and indelibly to the instrument or its data plate, and may only be applied once conformity is established.

Obligations by role

Manufacturers — meet the essential requirements, complete the correct conformity assessment with a notified body, compile technical documentation, draw up the EU declaration of conformity, and apply the CE and supplementary metrology markings plus the notified body number.
Authorised representatives — carry out the documented tasks the manufacturer delegates, including keeping the declaration and documentation available.
Importers — verify the assessment was done and the markings and documents are present, add their identification, and refuse non-compliant instruments.
Distributors — check the markings, declaration availability and instructions before making instruments available, and act with due care in storage and transport.

Enforcement

MID is a directive, so each Member State transposes it into national law and designates the authorities that enforce it and the notified bodies that perform conformity assessment. In Denmark, the Danish Safety Technology Authority (Sikkerhedsstyrelsen) is the competent authority for legal metrology and market surveillance of measuring instruments. National rules also govern the in-service use and periodic verification of many instruments once installed.

Market surveillance authorities can require corrective action, restrict or prohibit the making available of non-compliant instruments, order withdrawals or recalls, and act against improperly applied markings. Because measurement instruments underpin billing and trade, non-compliance can also expose operators to challenges over the validity of the transactions the instrument supported.

Getting compliant

Confirm whether your instrument falls within one of MID’s ten categories and identify the instrument-specific annex.
Determine the accuracy class, rated operating conditions and applicable essential requirements.
Select an authorised conformity assessment module path and engage a notified body listed in NANDO.
Compile technical documentation and draw up the EU declaration of conformity.
Apply the CE marking, the supplementary metrology marking (“M” plus year in a rectangle) and the notified body number.
Provide instructions and information with the instrument in the required languages.
Check national rules on installation, in-service use and periodic re-verification.

How Conphora helps

Conphora monitors MID and maps your instruments against the right category annex, conformity assessment module and marking requirements, flagging gaps in documentation, the declaration of conformity and the metrology marking before they become enforcement problems. The platform helps you generate and keep the right documentation, and alerts you when obligations change so your compliance stays current.

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Sources and further reading

This guide is for general information and is not legal advice.

Last updated: 12 June 2026