CEN and CENELEC have dedicated agreements with the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC), promoting the benefits of the international standards to international trade and markets harmonization. The high level of convergence between the European and international standards is facilitated by the ongoing technical cooperation between CEN and ISO (Vienna Agreement) and between CENELEC and IEC (Frankfurt Agreement).

The main objectives of these agreements are to provide a:

  • framework for the optimal use of resources and expertise available for standardization work;
  • mechanism for information exchange between international and European Standardization Organizations (ESOs) to increase the transparency of ongoing work at international and European levels.


CEN has an agreement for technical co-operation with the International Organization for Standardization (ISO). Through the involvement of experts in Technical Committees, European and national expertise is being developed and recognized globally.
The Vienna Agreement, signed in 1991, was drawn up with the aim of preventing duplication of effort and reducing time when preparing standards. As a result, new standards projects are jointly planned between CEN and ISO. Wherever appropriate priority is given to cooperation with ISO provided that international standards meet European legislative and market requirements and that non-European global players also implement these standards.
The Vienna Agreement allows expertise to be focused and used in an efficient way to the benefit of international standardization. It is completed by jointly developed Guidelines supporting the practical implementation of the Vienna Agreement.


CENELEC closely cooperates with its international counterpart, the International Electrotechnical Commission (IEC). In order to facilitate a consensus-finding process between European and international standards development activities in the electrical sector, CENELEC and IEC formalized the framework of their cooperation through the signature in 1996 of an 'agreement on common planning of new work and parallel voting', known as the Dresden Agreement.
The main purpose of the CENELEC-IEC cooperation is to avoid the duplication of work and to reduce time when preparing standards. As a result, new electrical standards projects are jointly planned between CENELEC and IEC, and where possible most are carried out at international level. This means that CENELEC will first offer a New Work Item (NWI) to its international counterpart. If accepted, CENELEC will cease working on the NWI. If IEC refuses, CENELEC will work on the standards content development, keeping IEC closely informed and giving IEC the opportunity to comment at the public enquiry stage. CENELEC and IEC vote in parallel (both organizations are voting in the same time) during the standardization process. If the outcome of the parallel voting is positive, CENELEC will ratify the European standard and the IEC will publish the international standard.
The Frankfurt Agreement
After 20 years of a fruitful partnership that has resulted in a very high level of technical alignment (close to 80% of CENELEC standards are identical to or based on IEC publications), CENELEC and IEC have reconfirmed their longstanding cooperation on 17 October 2016, by signing the Frankfurt Agreement. Building on the experience of both partners, this new agreement preserves the spirit and approach conveyed by the Dresden Agreement, in particular the strategic commitment of CENELEC to supporting the primacy of international standardization. It includes several update aiming to simplify the parallel voting processes, and increases the traceability of international standards adopted in Europe thanks to a new referencing system.