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How Often Should You Do Penetration Testing? Frequency Guide for Australian Businesses

If you are wondering about penetration testing frequency for your organisation, you are not alone. Most Australian businesses are told they should do a pen test, but not many are given a clear, risk-based answer on how often, or why.

The short version is that most organisations in Australia should run penetration testing at least once a year and also after major changes to systems or following a serious incident. From there, the right cadence depends on your risk profile, regulatory obligations and how often your environment changes.

 

 

 

There is no single mandated penetration testing frequency

There is no single law in Australia that says you must penetration test every X months. Instead, different standards and regulators expect you to test often enough to match your risk.

Examples:

  • APRA CPS 234 expects a systematic testing programme, where the nature and frequency of control testing (including penetration testing) aligns with how critical the systems are and how quickly threats and changes occur.

  • The Australian Signals Directorate and the ASD Essential Eight guidance emphasise ongoing validation of controls and regular reassessment, which many organisations meet by combining vulnerability scanning with periodic penetration testing.

  • Common industry practice in Australia is at least annual penetration testing, with more frequent testing in high-risk environments or where there are constant changes, such as online services and financial platforms.

So rather than chasing a magic number, you need a schedule that fits your environment, your compliance obligations and your appetite for risk.

A practical rule of thumb for Australian businesses

If you want a simple starting point, this is how I usually frame penetration testing frequency for Australian organisations.

Baseline: at least annually

For most small to medium Australian businesses, annual penetration testing is a sensible baseline.

Annual testing helps you:

  • Validate that security patches, configuration changes and other improvements are working in practice.

  • Gather evidence for boards, insurers and auditors that you are actively testing your controls.

For many professional services, healthcare, education and non‑APRA regulated organisations, once every 12 months plus when things change is a sound starting point.

Higher risk: 6‑monthly or quarterly

If your organisation is in a higher risk category, more frequent penetration testing is expected.

Examples include:

  • APRA‑regulated entities (banks, insurers, super funds) where CPS 234 requires a testing programme aligned to asset criticality and changing threats.

  • Online platforms with significant payment processing or sensitive personal information, where changes are frequent and the impact of a breach is high.

In these cases, a mix of quarterly testing for critical internet‑facing assets and annual testing for lower‑risk systems is common.

Event‑driven testing: after change or incidents

Frequency is not just about the calendar. Certain events should automatically trigger additional penetration testing.

You should budget for a pen test:

  • After major system changes, such as a new public‑facing application, migration to a new cloud platform, or a significant network redesign.

  • Before key audits or certifications (for example, ISO 27001 certification or SOC 2 attestation) to demonstrate your controls hold up under realistic attack.

  • After a significant security incident or near miss, to confirm that the root cause has been addressed and no further exploitable gaps remain.

Taken together, annual plus event‑driven testing is the minimum sensible penetration testing schedule for most Australian organisations.

 

 

How Australian regulations influence penetration testing requirements

Your penetration testing schedule should line up with your regulatory and contractual obligations, not sit off to the side.

APRA CPS 234 and regulated entities

For APRA‑regulated organisations, CPS 234 requires you to test the effectiveness of information security controls through a systematic testing programme. The frequency and depth of testing must match factors like the sensitivity of information, the rate of change and the potential impact of an incident.

While CPS 234 does not specify that penetration testing should be done every X months, regulators and independent assessors expect:

  • At least annual testing of critical systems, often more frequently for high‑value internet‑facing assets.

  • Independent testing that provides credible assurance to the board and senior management.

ASD Essential Eight and government‑aligned frameworks

The Essential Eight maturity model focuses on practical controls (patching, application control, multi‑factor authentication and so on), but recent guidance has increased emphasis on ongoing validation and reassessment.

Many organisations pursuing higher Essential Eight maturity levels now use penetration testing to:

  • Prove that controls are effective against realistic attack scenarios, not just configured in theory.

  • Provide technical evidence for internal and external assessments.

ISO 27001, SOC 2 and privacy obligations

ISO 27001 and SOC 2 both expect you to monitor and review control effectiveness, including technical testing of security controls. Penetration testing is a well‑recognised way to provide this evidence for Annex A controls in ISO 27001 and for relevant SOC 2 trust service criteria.

In parallel, the Privacy Act and the Notifiable Data Breaches scheme expect “reasonable steps” to protect personal information. Regular penetration testing of systems that process or store personal data is one way to demonstrate that those steps are in place and being maintained.

If you are using compliance automation platforms like Vanta or Drata to support ISO 27001 or SOC 2, penetration testing sits alongside automated checks. The platforms help you track controls and evidence, and a partner like Siege Cyber bridges the gap with experienced penetration testers who can provide the depth of technical validation auditors look for.

Building a penetration testing schedule that fits your organisation

Rather than just picking annual or quarterly testing, it helps to design a simple penetration testing plan across your environment.

A practical approach looks like this:

  1. Identify critical assets
    Focus first on internet‑facing applications, remote access points, cloud environments and systems that handle sensitive data or critical operations.

  2. Map regulatory and contractual obligations
    Check APRA CPS 234, Essential Eight targets, ISO 27001 or SOC 2 plans, as well as customer and vendor security requirements.

  3. Set risk‑based cadences
    Assign more frequent testing to high‑risk, high‑change systems, and annual testing to lower‑risk or more stable environments.

  4. Combine calendar and event‑driven testing
    Lock in annual testing, then add tests after major changes and before significant audits or compliance milestones.

If you want help translating this into a concrete plan, Siege Cyber’s penetration testing team can work with you to prioritise systems and map out a 12 to 24 month schedule that aligns with your obligations and budget.

If you would like a clearer view of where you stand today, reviewing your current testing approach as part of a broader security assessment (see the Protect Package) or Essential Eight assessment can be a useful starting point. Siege Cyber offers these assessments to help you identify gaps and build a roadmap, not just a one‑off report.

 

 

What happens if you do penetration testing too rarely?

Many organisations still treat penetration testing as something they do only when a client demands it or just before a certification audit. The problem is that systems, staff and attackers all change far more often than that.

Testing too rarely can mean:

  • Vulnerabilities remain exposed for years because they were introduced after the last test and never checked.

  • Boards, regulators and insurers question whether your security programme is actually working, because you cannot show recent, independent test results.

  • You only discover weak points after an incident, rather than through controlled testing on your own terms.

Industry surveys in recent years have shown that many of the high‑impact breaches traced back to missing patches or misconfigurations that could have been identified by basic testing earlier. Regular penetration testing is one of the ways to break that pattern.

 

How Siege Cyber approaches penetration testing for Australian organisations

Siege Cyber’s penetration testing services are designed for Australian businesses that need practical, evidence‑based testing aligned with local regulations and global best practice.

Our team performs:

  • Network, web application, API, cloud, internal and wireless penetration testing for organisations across sectors, with a focus on realistic attack scenarios and clear business impact.

  • Engagements that tie directly into frameworks like ISO 27001, SOC 2 and the Essential Eight, so that the output supports your broader security and compliance goals.

You can read more about our approach, methodology and deliverables on the Siege Cyber penetration testing service page: <https://siegecyber.com.au/services/penetration-testing/>.

For organisations planning ISO 27001 certification or SOC 2 readiness, Siege Cyber’s partnership with Vanta and Drata means we can combine platform automation with hands‑on testing and advisory, giving you both streamlined evidence collection and real‑world technical assurance.

If you would like a sense of typical penetration testing costs and how frequency affects pricing, Siege Cyber publishes transparent guidance on our pricing page: <https://siegecyber.com.au/#pentest-pricing>.

 

Siege Cyber's SOC 2 consulting team based in Brisbane, Australia

 

Next steps: set a sensible testing rhythm

If your organisation does not have a clear answer to “when is our next penetration test scheduled and why that date”, now is the time to set that rhythm.

Siege Cyber can help you:

  • Review your current testing history and regulatory obligations.

  • Design a risk‑based penetration testing schedule that balances assurance, cost and business impact.

  • Deliver the testing, reporting and remediation support so that findings turn into real improvements.

To discuss the right penetration testing frequency for your business, get in touch via siegecyber.com.au or email [email protected] and we can talk through your environment, obligations and options.