Organisation providing essential services designated under NIS Regulations with mandatory security requirements.
An Operator of Essential Services (OES) is an organisation providing services essential to society's functioning—energy suppliers, water companies, healthcare providers, transport operators—designated under NIS Regulations. OES must implement appropriate security measures, report significant incidents, and undergo regulatory oversight. Sector regulators maintain lists of OES in their domains. OES designation brings mandatory security requirements and potential enforcement action for non-compliance.