An organisation that performs certification, testing, calibration, inspection or other conformity assessment services can seek accreditation. An accredited body has demonstrated that it fully meets the requirements of relevant national and international standards.

The criteria for determining a certification body’s competence are based on the relevant national or international standard (such as ISO/IEC 17065, ISO/IEC 17021-1 or ISO/IEC 17025) and may include: the qualifications required, knowledge and skills, training and experience of staff; appropriate equipment that is properly calibrated and maintained; adequate quality assurance procedures; and appropriate sampling practices.

Accredited bodies can be private or government-owned, and can range in size from sole traders to large multi-disciplinary, multi-site organisations.