Certification bodies are accredited by the national data protection authorities (DPA) or by the national accreditation body (named in accordance with Regulation 17065/2012). For further information regarding certification bodies, we recommend contacting the national DPA in your country. You can find an overview of all EEA DPAs here.
You can find further information regarding accreditation of certification bodies here: Guidelines 4/2018 on the accreditation of certification bodies under Article 43 of the General Data Protection Regulation (2016/679)