Why Annual Pentests Leave You Exposed 351 Days
If you are asking how often penetration testing should happen, the short answer is more than once a year. A single annual pentest only captures your security posture on the day it runs. New vulnerabilities, new code releases, and new staff and vendor access appear every week after that, which means an annual-only testing schedule leaves your organisation genuinely exposed for most of the year.
The exposure window math: a typical pentest engagement covers roughly 10 to 14 days of testing time inside a 365-day cycle. That leaves around 351 days where your environment has changed but has not been re-tested.
This gap is not hypothetical. Every deployment, every new SaaS integration, and every configuration change is a chance for a new weakness to appear. A test result from March tells you very little about your risk in October, yet many organisations still treat one test as a full year of assurance.
An annual cadence is also the baseline most Australian organisations default to because it satisfies a compliance checkbox. According to the Essential Eight maturity model, regular testing is treated as a baseline expectation, not a ceiling. Higher maturity levels expect testing to happen more often as an organisation’s risk profile grows.
In our engagements with Australian SMEs and mid-market IT teams, we consistently see the same pattern: the incidents that catch organisations off guard are rarely the vulnerabilities found in the last report. They are the ones introduced afterward, in the 351 days nobody was looking. This blog breaks down what actually changes between tests, what a realistic testing cadence looks like by budget, and where a full vulnerability assessment and penetration testing engagement fits against lighter-weight retesting options.
What Actually Changes Between Pentests
A pentest report is a snapshot, not a subscription. The moment testing finishes, your environment keeps moving. Globally, an average of around 131 new CVEs are disclosed every day according to the National Vulnerability Database, and any one of them could affect software already running in your stack. Here is what tends to shift in the months after a test.
New Code and Releases
Every feature release, API change, or refactor is a chance to reintroduce a flaw the last test already cleared.
New Third-Party Vulnerabilities
Libraries and platforms you did not touch can still become exploitable when a new CVE is disclosed against them.
New Vendors and Integrations
Each new SaaS tool or API integration expands your attack surface in ways the original test scope never covered.
Staff and Access Changes
Onboarding, offboarding, and permission changes accumulate quietly and are rarely revisited between tests.
Configuration Drift
Firewall rules, cloud settings, and access controls get adjusted for convenience and rarely get reverted.
In practice, we see automated vulnerability scanning catch a good share of this drift between full engagements, but scanning and penetration testing answer different questions. If you are unsure which one applies to your situation, our breakdown of what auditors accept as scanning versus pentesting covers where each one fits.
Testing Cadence Options by Budget
There is no single right cadence for every organisation. The right frequency depends on how fast your environment changes, what compliance frameworks apply, and what you can reasonably budget each year. The table below outlines three common tiers we scope for Australian clients, from a compliance baseline through to continuous assurance.
Frameworks differ in what they expect here. PCI DSS requires penetration testing at least annually and after any significant change, alongside quarterly vulnerability scanning as a separate, ongoing requirement. That distinction alone is often the reason a business needs to move up a tier.
| Tier | Best For | Testing Cadence | Typical Annual Investment (AUD) |
|---|---|---|---|
| Compliance Baseline | SMEs meeting minimum audit or client requirements | 1 annual pentest plus quarterly vulnerability scanning | Indicative from $8,000 to $15,000 |
| Active Risk Management | Scaling SaaS, e-commerce, and growing IT estates | 2 pentests per year plus monthly scanning | Indicative from $18,000 to $35,000 |
| Continuous Assurance | Fintech, healthcare, and government contractors under strict compliance | Quarterly pentests plus continuous automated scanning | Indicative from $40,000 and up |
These ranges are indicative starting points, not fixed quotes. Actual cost depends on the size of your environment, the number of applications and networks in scope, and how much of the testing can be automated versus manual. Most clients we work with start at the Compliance Baseline tier and move up as their attack surface or compliance obligations grow.
The Retest and Rescan Middle Path
Not every organisation is ready to jump from one annual pentest straight to a Continuous Assurance budget. In our engagements, the most common next step is not a bigger test, it is a smarter pairing of two lighter-weight activities in between full engagements: targeted retesting and automated rescanning. Neither replaces a full pentest, but together they close most of the exposure gap for a fraction of the cost.
Retesting
A focused, manual check that verifies specific findings from your last pentest were actually fixed, not just marked as resolved.
Best triggered right after a remediation cycle, or after a significant change to the systems that were originally in scope.
Rescanning
Automated vulnerability scanning run on a fixed schedule to catch newly disclosed CVEs, exposed ports, and misconfigurations across your whole environment.
Best run monthly or quarterly, so drift is caught in weeks rather than discovered at the next annual test.
The pairing works because each one covers what the other misses. Rescanning is fast and cheap but only catches known, signature-based issues. Retesting is manual and targeted, so it validates exploitability and business logic that automated tools cannot see. Used together between full pentests, they turn the 351-day gap into a series of much shorter windows.
