Measuring Instruments Directive (MID) 2014/32/EU

Last reviewed: May 2026 · Legal status verified against EUR-Lex.

Directive 2014/32/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments — the "MID" — replaced Directive 2004/22/EC and has applied since 20 April 2016. It covers ten categories of measuring instruments used in legal metrology applications: trade, calculation of duties, public health and safety, environmental protection. The MID's structure is unusual: a horizontal text plus ten product-specific annexes (MI-001 to MI-010) setting specific requirements for each instrument category. Published as OJ L 96, 29.3.2014, p. 149.

Legal status and timeline

• Adoption: 26 February 2014.
• Date of application: 20 April 2016.
• Repeal of Directive 2004/22/EC: 20 April 2016.
• Status in May 2026: applies.

Scope: products covered

Article 1 applies to the measuring instruments specified in the ten Annexes MI-001 to MI-010:

• MI-001 — Water meters;
• MI-002 — Gas meters and volume conversion devices;
• MI-003 — Active electrical energy meters;
• MI-004 — Heat meters;
• MI-005 — Measuring systems for the continuous and dynamic measurement of quantities of liquids other than water (e.g., fuel dispensers);
• MI-006 — Automatic weighing instruments;
• MI-007 — Taximeters;
• MI-008 — Material measures (length, capacity);
• MI-009 — Dimensional measuring instruments;
• MI-010 — Exhaust gas analysers.

Each Annex sets accuracy classes, operating conditions, and instrument-specific essential requirements in addition to the general requirements in Annex I.

General essential requirements (Annex I)

Annex I sets common requirements for all in-scope instruments: allowable errors, reproducibility, repeatability, discrimination and sensitivity, durability, reliability, influence quantities, suitability, protection against corruption, marking. The instrument-specific annexes add accuracy classes and quantitative limits.

Conformity assessment procedures

Article 17 and Annex II provide a menu of modules. Manufacturers choose from the modules listed in the relevant instrument-specific annex (each MI annex lists permitted modules). Common combinations:

• Module B (EU type-examination) + Module D (production QA), Module E (product QA), or Module F (product verification);
• Module G (unit verification) for one-off instruments;
• Module H1 (full quality assurance with design examination) for some categories.

Notified Body involvement is mandatory for all categories. The four-digit identification number appears next to the CE marking. See Notified Bodies.

The "M" supplementary metrology marking

Article 22 requires, in addition to the CE marking, the supplementary metrology marking. The supplementary marking consists of the capital letter "M" and the last two digits of the year of its affixing, enclosed in a rectangle. The Notified Body identification number follows. This combined marking — "CE M21 1234" for example — identifies the year of conformity assessment and the Notified Body. The supplementary marking is unique to the MID and the Non-Automatic Weighing Instruments Directive.

Technical documentation

Annex II Module-specific provisions set the documentation contents. Retention: 10 years (Article 7(7)). See technical documentation.

EU Declaration of Conformity

Article 18 and Annex XIII. See EU Declaration of Conformity.

National metrological supervision after CE marking

The MID harmonises placing on the market. Member States retain extensive competence over verification in use (re-verification after installation, periodic verification, repair re-verification), which is not within the MID's scope. National legal-metrology authorities supervise these in-service obligations.

Harmonised standards and normative documents

The MID uses two parallel categories of compliance references: harmonised standards (EN) and "normative documents" (OIML — International Organization of Legal Metrology — recommendations). Article 14 provides that compliance with OIML normative documents listed in the OJEU also produces a presumption of conformity, in addition to EN harmonised standards. Examples: OIML R 49 (water meters), OIML R 137 (gas meters), OIML R 46 (electricity meters), OIML R 117 (dynamic liquid metering).

Recent and upcoming changes

The MID has been subject to several Commission delegated acts amending Annexes to align technical references. No structural amendment of the Directive is in train. The Commission has prioritised digitalisation of metrology (e.g., smart meters under MI-003) and harmonisation with the eIDAS Regulation and energy data spaces, but these touch the in-service regime rather than the MID's placing-on-market provisions.

Related legislation

• Non-Automatic Weighing Instruments Directive 2014/31/EU — companion regime for non-automatic instruments (separate Directive, similar structure).
• Low Voltage Directive 2014/35/EU — electricity meters and some other electronic instruments are excluded from the LVD; the MID applies in their place.
• EMC Directive 2014/30/EU — applies in parallel for EMC of MID-covered instruments.
• ATEX Directive 2014/34/EU — applies in parallel where instruments are used in explosive atmospheres.
• Directive 2009/72/EC and successors on the internal electricity market — for the deployment of smart meters and consumer-facing measurement.

Common errors

• Missing supplementary metrology marking. The "M" + year + NB number must accompany the CE mark. Affixing only CE is a documentary infringement.
• Wrong accuracy class. Each MI Annex sets accuracy classes (e.g., MI-001 distinguishes classes for cold water, hot water, indirect billing). Mis-assignment of class affects conformity throughout.
• Using OIML normative documents without OJEU listing. Only OIML documents whose references are published in the OJEU produce the presumption of conformity.
• Treating MID conformity as discharging in-service verification. The MID covers placing on the market; in-service verification is a national competence.

Sources

• Directive 2014/32/EU (MID) — EUR-Lex consolidated text.
• European Commission — Legal metrology sector.
• OIML — International Organization of Legal Metrology.
• Commission Notice — Blue Guide 2022 — EUR-Lex.