What are the 4 security classifications?

The Four Levels of Security Clearance in Australia

When it comes to national security and access to sensitive information, Australia operates a structured system of security classifications. These are not just bureaucratic labels—they determine exactly who can view or handle certain types of protected data. There are four main levels of security clearance, each building on the last in terms of scrutiny and trust.

The first and most basic level is the Baseline Vetting clearance. This is typically required for roles with minimal exposure to classified material, such as some civilian or contractor positions within government agencies. It involves checks on identity, citizenship, and a basic criminal history review.

Next is Negative Vetting Level 1 (NV1), which allows access to PROTECTED-level information. This clearance requires a more thorough background check, including employment history and reference verification. It's common in roles that regularly interact with sensitive government systems or data.

Negative Vetting Level 2 (NV2) steps up the scrutiny further. It’s often required for defense personnel or public servants working with highly sensitive information. This level includes deeper personal and financial checks, ensuring individuals are less vulnerable to coercion or compromise.

The highest level commonly issued is Positive Vetting (PV). Reserved for roles with access to TOP SECRET or STRATEGIC information, this clearance involves an in-depth assessment of a person’s background, associations, lifestyle, and foreign connections. Unlike the negative vetting levels, which assume clearance unless risk is found, Positive Vetting actively confirms an individual’s reliability and loyalty.

These classifications ensure that access to sensitive information is both necessary and secure. As of 2026, they remain a cornerstone of Australia’s security framework, balancing operational needs with national protection.