Since its establishment, the OIML has developed a number of guidelines to assist its Members, particularly developing nations, to draw up appropriate legislation concerning metrology across all facets of society and guidelines on certification and calibration requirements of new products, particularly where such calibration has a legal impact such as in trade, health care and taxation.

The word "regulatory" encompasses the "legal" aspects of the term – the role played by governments, national metrology institutes and standards organisations in creating a framework to ensure confidence in the accuracy and reliability of a measurement.

[4] Under French law, its principal body, the International Conference on Legal Metrology, is accorded diplomatic status.

At the 2011 meeting in Prague of the International Committee of Legal Metrology (CIML), the OIML updated its mission to read:[6] The mission of the OIML is to enable economies to put in place effective legal metrology infrastructures that are mutually compatible and internationally recognised, for all areas for which governments take responsibility, such as those which facilitate trade, establish mutual confidence and harmonise the level of consumer protection worldwide.At the same meeting, its objectives were then stated as follows:[6] The OIML, which has an annual operating budget of about two million euros that comes from Member subscriptions[7][Note 1] is organised around a three-layer model:[4][8][9] The overall direction of the OIML is vested in the International Conference (French: Conférence internationale de Métrologie légale) which meets every four years.

Secretarial services, day-to-day running and financial management of the OIML are provided by the BIML (French: Bureau International de Métrologie légale).

[14] Member States Albania Algeria Australia Austria Belarus Belgium Brazil Bulgaria Cambodia Canada Colombia China Croatia Cuba Cyprus Czech Republic Denmark Egypt Ethiopia Finland France Germany Greece Hungary India Indonesia Iran Ireland Israel Italy Japan Kazakhstan Kenya Korea Monaco Montenegro Morocco Netherlands New Zealand North Macedonia Norway Pakistan Poland Portugal Romania Russia Saudi Arabia Serbia Slovakia Slovenia South Africa Spain Sri Lanka Sweden Switzerland Tanzania Thailand Tunisia Turkey Ukraine United Kingdom United States Vietnam Zambia Corresponding Members Angola Argentina Azerbaijan Bahrain Bangladesh Barbados Benin Bolivia Bosnia and Herzegovina Botswana Burkina Faso Chinese Taipei Costa Rica Djibouti Dominican Republic Ecuador Estonia Fiji Gabon Georgia Ghana Guatemala Guinea Guyana Hong Kong Iceland Iraq Jordan Kiribati Kuwait Kyrgyzstan Latvia Lithuania Luxembourg Madagascar Malawi Malaysia Mali Malta Mauritius Mexico Moldova Mongolia Mozambique Namibia Nepal Nigeria Oman Panama Papua New Guinea Paraguay Peru Philippines Qatar Rwanda Saint Lucia Seychelles Sierra Leone Singapore Sudan Trinidad and Tobago Uganda United Arab Emirates Uruguay Uzbekistan The technical work of the OIML is carried out by Technical Committees (TC), each committee having responsibility for a different aspect of legal metrology.

The Technical Committees are:[15] The OIML produces a number of publications, including: Vocabularies (prefixed by the letter "V") that provide standardised terminology in the field of metrology.

The OIML has produced two principal works: In addition, the OIML was a partner in the JCGM[Note 2] which produced the International vocabulary of metrology - Basic and general concepts and associated terms (VIM), a document published by the BIPM on behalf of the JCGM Recommendations (prefixed by the letter "R") which are model regulations that establish the metrological characteristics required of certain measuring instruments and which specify methods and equipment for checking their conformity.

International Documents (prefixed by the letter "D"), which are informative in nature and intended to improve the work of the metrological services.

The aim of the OIML-CS is to facilitate, accelerate and harmonise the work of national and regional bodies that are responsible for type evaluation and approval of measuring instruments subject to legal metrological control.

The objectives of the OIML-CS are a) to promote the global harmonisation, uniform interpretation and implementation of legal metrological requirements for measuring instruments and/or modules, b) to avoid unnecessary re-testing when obtaining national type evaluations and approvals, and to support the recognition of measuring instruments and/or modules under legal metrological control, while achieving and maintaining confidence in the results in support of facilitating the global trade of individual instruments, and c) to establish rules and procedures for fostering mutual confidence among participating OIML Member States and Corresponding Members in the results of type evaluations that indicate conformity of measuring instruments and/or modules, under legal metrological control, to the metrological and technical requirements established in the applicable OIML Recommendation(s).