ATO meaning

ATO (authority to Operate) describes the formal approval given by a competent organisation (for example, a government department, regulator or senior risk owner) allowing a defined system, service or facility to go live and operate. In contracts, the “holder” is the supplier or operator to whom the approval is issued for the specified scope. ATO is not usually a statutory term. It is a descriptive expression arising from government security and risk-management practice (including NCSC guidance and sector policies, notably in defence and wider public sector). It is often treated as part of, or alongside, security accreditation or go‑live authorisation. Key features: - Scope- and environment-specific; commonly time-limited and conditional. - Dependent on maintaining agreed controls and assurance (for example, security cases/RMADS or equivalents, penetration test results and data protection impact assessments). - Can be withheld, suspended or withdrawn if conditions are not met or risk changes. Typical contractual issues: - Responsibility for obtaining and maintaining ATO; evidence, audit and incident-reporting obligations. - Customer dependencies (information, environments, approvals). - Consequences of delay/refusal (impact on milestones, payments, liquidated damages or termination). Usage is broadly consistent across England and Wales, Scotland, Northern Ireland and Ireland, though the approving body and detailed policy framework vary by sector and organisation.