What is accreditation?

Accreditation is the international tool used to generate confidence in the correct performance of a very specific type of activity called Conformity Assessment Activities, which include testing, calibration, inspection, certification and verification, among others. In general, any activity that assesses whether a product, service, system, installation, etc. conforms to certain requirements can be subject to accreditation. These requirements may be stipulated by law and, therefore, be of a mandatory nature or be specified in standards, specifications or other documents of a non-regulated nature.

The value of conformity assessment activities depends largely on the credibility of the assessors performing them and the confidence that the market and the wider community places in them. To achieve this confidence and credibility, it is necessary to set up an independent, stringent and global mechanism that will assure the technical competence of these assessors and their compliance with international standards – and that is exactly what accreditation is.

The Accredited Entities...

  • They have staff with the appropriate expertise and experience.
  • They have the necessary and appropriate equipment and infrastructures for carrying out their activities.
  • They apply appropriate and valid assessment methods and procedures.
  • They employ techniques to assess the quality of results and ensure the traceability of the measurements and calibrations associated with their services.
  • They report sufficiently to their clients on the results of their activities, issuing clear and precise reports or certificates.


To determine the technical competence of conformity assessment bodies, ENAC uses as a benchmark the requirements of international standards, which form the basis for the signing of global recognition agreements.

Below are the standards used for each type of assessment (if in doubt about the applicable standard in your case, click here).

  • Testing Laboratories UNE-EN ISO/IEC 17025
  • Calibration Laboratories UNE-EN ISO/IEC 17025
  • Clinical Laboratories UNE-EN ISO 15189
  • Inspection Bodies UNE-EN ISO/IEC 17020
  • Bodies Certifying Products UNE-EN ISO/IEC 17065
  • Management System Certification Bodies UNE-EN ISO/IEC 17021
  • Personnel Certification Bodies UNE-EN ISO/IEC 17024
  • Environmental Verifiers Regulation EC 1221/2009
  • Greenhouse Gas Emission Verifiers EA-6/03, UNE-EN ISO 14065, Regulation EU 600/2012
  • Providers of Proficiency Testing Schemes UNE-EN ISO/IEC 17043
  • Reference Material Producers, ISO Guide 34

For entities that must comply with Good Laboratory Practices (GLP) -studies of plant protection products, industrial chemicals, etc. – the requirements are set out in Royal Decree 1369/2000.



UNE, EN and ISO standards are private-sector documents subject to the laws protecting intellectual property rights, and must therefore be purchased from their respective copyright holders. We therefore suggest that you apply to the Asociación Española de Normalización, AENOR, the Spanish standardisation association.

ENAC and the international accreditation organisations also publish documents containing criteria to clarify or add detail to the different standards and, on occasion, to make them specific to certain sectors. All ENAC documentation relative to accreditation criteria and procedures can be found in the DOCUMENTS section.

Find out more on accreditation and on the impact it has on our day-to-day work