Penetration testing can reveal a lot of information, but the usefulness of the tests lies in the assumption that the tests are carried out to mirror the current situation of your organization. The challenge comes from the fact that the IT environment of any company changes over time.
New programs are deployed, new services are added, new employees are hired, and the network topology changes internally. Penetration testing that showed everything okay six months ago is unlikely to give an accurate reflection of your current situation.
This does not mean that there should be continuous testing of your business. It means that the tests should be carried out in line with how much change has occurred.
UK Government Digital Service standards recommend pen testing at least every 12 months. ISO 27001 links testing frequency to your risk assessment, though most certified organisations will default to annual as their baseline anyway. There is also a requirement for PCI DSS; you will need an annual pen test, as well as additional pen tests every time there is a major change in your infrastructure.
NCSC doesn’t pin down a specific number. Their guidance does assume regular, repeated engagements though, not one-off jobs you never follow up on. Look across all these frameworks and the message is consistent: test at least once a year, then test again whenever something meaningful changes.
Annual testing provides you with a baseline. This is its purpose. But if your business goes through a big change between scheduled tests and you just sit on your hands until next year, you’re gambling with your security posture, and it’s a gamble that doesn’t pay off often enough to be worth taking. These are the most common triggers that should prompt an off-cycle test:
Combine an annual fixed test with a written policy on additional tests. Define what counts as a “significant change” for your organisation specifically, write it down and stick to it. Don’t leave it vague enough that people can argue their way out of testing.
More CREST-accredited firms now structure engagements around infrastructure events instead of calendar dates, and Equilibrium Security penetration testing is one example of how that model works in practice. If your current provider still quotes a flat annual test with no flexibility for mid-year triggers, that’s a conversation worth having.
In addition to manual penetration testing, conduct an automated vulnerability scan at least once per month or quarter. It’ll catch newly disclosed CVEs and configuration drift that creeps in over time. Automated scanning won’t replace a proper manual pen test, but it fills the gap nicely and gives your security team something concrete to act on while they wait for the next full engagement.
Testing annually should be considered as the baseline. It’s the minimum, not a target to aim for. Businesses that actually get value from pen testing will tie their schedule to how the company operates in practice, not to an arbitrary date on a calendar.
Define your triggers undoubtedly, combine scheduled tests with continuous scanning, keep your testing policy updated as your risk profile develops, and don’t wait for someone else to find the gaps before you do.
For most companies, conducting a pen test once a year is sufficient. But sometimes, more frequent pen testing is required depending on the changes that have occurred within the company’s system.
Some common triggers for additional pen tests include cloud migrations, application deployments, mergers, third-party integrations, office moves, and firewall changes.
Where a new application, API, or customer portal is dealing with sensitive data or provides new features, then testing prior to launch would be beneficial.
An ideal way would be to establish a base for annual testing, set some criteria for off-cycle testing, and incorporate vulnerability scanning between full tests.
