This document gives guidance to the CEN technical bodies as well as to the CEN-CENELEC Management Centre (CCMC) on how to handle requests for A-deviations in ENs, keeping in mind that A-deviations should be considered as exceptional.


When drafting European standards, the intent should always be to ensure no conflict with national regulations. If, however, potential conflicts are identified, the responsible TC should make every effort to avoid the conflict. However, cases may arise where this is not possible, and a CEN member is confronted with a situation where it would have to implement an EN that is not compliant with the regulation of its country. It is then the full right of this CEN member, and this right cannot be denied, to ask for derogation from the application of the standard in its country. This derogation is exercised through the application of an A-deviation.

Nevertheless, national regulation may later be withdrawn or modified, therefore calling for a review of the compatibility of the European Standard with the new regulatory context.

NOTE: National regulation comprises legal acts that are enforceable as law in a CEN member country. Due to differing legal systems and languages in Europe, such legal acts can have different forms and names (law, decree, order, binding precedent) and include jurisprudence if relevant.


2.1  Information that the provisions of an EN are in conflict with national regulation shall be included in an Annex to the European Standard, called A-deviation. The exceptional aspect of the A-deviation should be taken into account as soon as possible, preferably when new work is approved.

2.2  When conflict between provisions of a draft European standard and national regulation(s) is identified, responsible TC should make every effort to amend the draft in order to avoid the conflict, without creating new conflicts, with other national regulations, particularly if there is a number of countries requesting similar A-deviations.

2.3  When it is impossible to avoid A-deviations, all relevant information concerning them (clear identification of the national regulation concerned and of the normative clauses of the standard in conflict with the regulation) is laid down in an informative annex to the EN in accordance with CEN-CENELEC Internal Regulation - Part 2, Annex E and CEN-CENELEC Internal Regulation - Part 3, Annex ZB.

2.4  A-deviations are only based on conflicting national regulation. They are out of the competence of CEN members in charge of implementing ENs as national standards. It is the reason why only the NSBs concerned by conflicting national regulation can ask for an A-deviation. An A-deviation should only reflect an issue with national regulation and is not a privilege granted to a CEN member.

2.5  Attention should be paid in particular to those cases where the national regulation in question is in conflict with EU harmonization legislation. It is not in the remit of CEN to assess and decide if the national regulation is in conflict or not with the EU/EEA harmonisation legislation.


  • For EEA countries it is expected that there is no conflict between the National regulation and the EU/EEA harmonisation legislation.
  • For non-EEA countries having an agreement with the EU and demonstrating regulatory convergence or compatibility with the essential regulations that support the Single market in areas that are relevant to CEN activities, conflict between their national regulation and EU/EEA harmonisation legislation is expected to be limited given the link between those countries and EU/EEA.

2.6  For standards intended to be offered for citation in OJEU, TCs should make every effort to draft the EN in such a way that A-deviations are not needed for those clauses related to the fulfilment of essential requirements of the European legislation

2.7  A-deviations do not release CEN members from their obligation to implement the relevant European Standard.

2.8  The Technical Board monitors the use of A-deviations, such as:

  • Number of A-deviations over the catalogue (both ENs and hENs);
  • Number of A-deviations per Member (both ENs and hENs);
  • Number of A-deviations over a piece of legislation;
  • Number of A-deviations for piece of legislation/Member.


3.1  The product, service or practice specified by the European Standard is banned in a given country

The common endeavour of most CEN members does not necessarily need to stand still because of a ban in a single country. In such cases, the national regulation does not allow to place in the market or to use products, within the scope of the European Standard, in a CEN member country. However, the standard remains useful for national manufacturers since the product could still be produced in this country even it is not allowed to use it there. This applies analogously also to services and practices specified by a European Standard. The European Standard can make users aware of the situation, by means of an A-deviation covering all the requirements of the EN.

3.2  National regulation has requirements other than the European Standard

Such cases do not require any action of CEN and CENELEC, simply because compliance with regulations is mandatory and compliance with standards is voluntary.

3.3  National regulation has requirements more demanding than the European Standard

As compliance with national regulation is mandatory in the respective country, an A-deviation makes standard users aware that compliance with the standard is not sufficient in this country.

3.4  National regulation has less requirements or requirements less demanding than the European Standard

When they exist, requirements in national regulation are often less precise or stringent than those of the European Standard. In the absence of contradiction, it is the user who makes the voluntary choice to comply only with the national regulation, or to implement the best practices embedded in the European Standard.

3.5  Binding precedents and jurisprudence

The legal requirement faced by users is not limited to codified acts passed by the legislator or the executive, and can take the form of binding precedents, rulings or jurisprudence established by courts, which may form part of the national legal framework. Such compulsory requirements, if deemed contradictory to the European Standard, can be dealt with by means of an A-deviation provided it is fully, convincingly and verifiably documented.

3.6 National regulation under Directive (EU)2016/797

In exception to the process and obligation described in 4.1, Members shall not request an A-deviation if this A-deviation is based on national rules subject to the procedure of Article 14 of Directive (EU) 2016/797 of the European Parliament and of the Council of 11 May 2016 on the interoperability of the rail system within the European Union. Such national rules must be notified to the European Union Railways Agency (ERA) following the procedure described in the Directive. The Agency examines and publishes the national rules, both accepted and rejected, under Directive 2016/797/EU, on the following registers: https://rdd.era.europa.eu/rdd/Default.aspx and https://srd.era.europa.eu/home.

NOTE 1: This exception does not apply to the cases of A-deviation requests based on national regulation related to the infrastructure, vehicles and networks stated in art. 1 paragraph 3 of the Directive 2016/797/EU (which are excluded of the scope of the Directive) and art. 1 paragraph 4 of the Directive (infrastructure and vehicles that Member states may exclude from the scope of the measures implementing the Directive).

NOTE 2: This exception does not apply to the cases of requested A-deviations based on national regulation taken by members subject only to the COTIF rules. But these Members shall avoid requesting A-deviations based on measures deviating to the Annex G of The Convention concerning International Carriage by Rail (COTIF) (Uniform Rules concerning the Technical Admission of Railway Material used in International Traffic).


4.1  Risks of conflicts between national regulation and a future EN shall be identified as soon as a new subject of work is proposed. An early notification allows the TC to adapt its draft in order to avoid the request for an A-deviation.

CEN Members should inform the relevant TC of their need to request an A-deviation as soon as the drafting starts and at the latest during the CEN Enquiry.

Although it is always useful to obtain this information, regardless of the stage of the standard's development, any late notification may require an amendment of the European Standard as soon as it is published. Nevertheless, it is understood that there may be cases where national regulation has changed or has been introduced in parallel with the development of the standard.

4.2  The request for a possible A-deviation shall contain:

  • a critical examination of the national situation in regard of the legal requirements of its national regulation;
  • the title, date and the relevant clauses/elements of the national regulation;

The member presenting a request for A-deviation shall provide an informal translation of the relevant part(s) of the national regulation into the working language of the Technical body.

  • the reference(s) of the standard(s) affected by this request;
  • the reference(s) of the clause(s) of the draft(s) concerned by this A-deviation, or the indication that the A-deviation affects the standard(s) in its whole.

A member shall examine its national situation critically before making a request for a deviation to the Technical body as appropriate.

4.3  The TC is responsible for assessing the material presented in support of the request for the A-deviation. The role of TC is restricted to verifying whether there is a conflict between the EN and national regulation, on the basis of the evidence provided by the NSB  requesting it, which needs to be:

  • fully documented,
  • convincing, and
  • verifiable

When considering if an EN should be redrafted to avoid A-deviation, the TC should take the following elements into consideration:

  • Are the elements covered by the A-deviation related to safety, health or environmental aspects?
  • Can the standard be correctly used with modification of the elements included in the A-deviations?

The TC is not entitled to assess or even challenge national regulation.

4.4  Any TC, when receiving such a request, should:

  • adapt as far as possible the draft to avoid the A-deviation;
  • verify whether or not the regulation is relevant, i.e. whether there is actually a contradiction between (a) requirement(s) in the national regulation and (a) normative requirement(s) in the (pr)EN.

4.5  In case the request for A-deviation is not considered justified, any TC  should inform the notifying member about it. In case of disagreement, the notifying member can lodge an appeal to BT.

4.6  When the request for A-deviation is considered justified, any TC should:

  • document the result of the verification by a TC decision;
  • draw the attention of the standards users, in the foreword of the EN, to the existence of deviation(s) from the content of the EN due to national regulation;
  • list the countries having such an A-deviation, all relevant information concerning them (clear identification of the national regulation concerned and of the normative clauses of the standard in conflict with the regulation), in an informative annex to the EN;
  • finalize the draft and submits it to CCMC, via the Submission interface, in order to start the Enquiry or Formal Vote

4.7  In justified cases, a modification to or inclusion of the A-deviation might be required after the Formal Vote.

Requests for -- or modifications to -- A-deviation made after the standard has been voted upon or made available require BT approval through a vote by correspondence according to IR2 6.1.4. The result is published as an Amendment if the standard has already been made available. If the standard is not yet made available, the results are incorporated into the text before publication.

4.8  Review

A question concerning the validity of A-deviations is included in the 5-year systematic review balloting.

The TC is invited to verify, together with the relevant NSB, that A-deviations are still relevant and valid when its deliverables undergo systematic review.

If an A-deviation is no longer valid, the member shall notify it and the EN shall be updated accordingly (through an amendment, even if the standard is older than 4 years, or a revision).


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