Penetration testing frequency Industry-specific best practices

Recommended penetration testing frequency by industry

Annual penetration testing: the bare minimum for security compliance

Annual penetration testing serves as the baseline for cybersecurity best practice and can help businesses identify and address vulnerabilities before they turn into exploitable threats. While some businesses assume that once a year pen testing is sufficient, it’s worth understanding that it is a minimum requirement rather than a comprehensive security strategy.

Why is annual penetration testing necessary?

For many organisations, annual penetration testing is either required by compliance frameworks or strongly recommended as best practice to enhance regulatory compliance, such as:

• ISO 27001 – Regular vulnerability assessments are required as part of an organisation's Information Security Management System (ISMS), while pen testing is accepted best practice for maintaining certification.
• PCI DSS – Mandates businesses handling payment card data (e-commerce, financial services) to conduct penetration testing at least annually and after significant infrastructure changes.
• GDPR – It is more of a best practice in that organisations implement appropriate security measures to protect the data of their users, while pen testing is considered best practice to demonstrate proactive compliance.
• NHS Data Security and Protection (DSP) Toolkit – Regular pen testing is strongly recommended to meet the mandatory data security requirements.
• SOC 2 (Service Organisation Control 2) – SOC Type II requires continuous monitoring with annual testing as widely accepted best practice.

Businesses that typically require annual pen testing

Some businesses and industries will find that annual pen testing will suffice, especially those with low risk exposure and infrastructure that changes infrequently.

• Non-regulated industries and small businesses – local retailers, small service providers, and other businesses that do not handle sensitive customer data can often meet security best practices with annual testing.
• Professional service firms – Small firms within the legal, financial, or consultancy space without complex IT infrastructure may only require annual testing, especially if third-party cloud services are relied upon for data security.
• Companies with stable IT environments – compared to businesses that undergo frequent infrastructure changes, those with static infrastructure and strong internal security policies may require less frequent pen testing.

Limitations of annual pen testing

Annual penetration testing helps businesses meets compliance and to reduce the security risks, but it should not be the only security measure in place. As we know, threats evolve rapidly and to rely on once-a-year testing means an extended period where vulnerabilities are left undetected posing a real risk to a business.

If your business handles sensitive data, financial transactions or customer data then you should consider more frequent pen testing or complementary security measure, such as continuous security monitoring and vulnerability scanning which Bulletproof offers with every penetration test package.

Quarterly and semi-annual penetration testing: meeting high security demands

Organisations in high-risk industries handling sensitive customer data, financial transactions, or critical services are prime targets for cyberattacks, and annual pen testing alone is not enough. These businesses would benefit from quarterly or semi-annual penetration testing to maintain strong security defences. Industries that have high transaction volumes or face strict compliance regulations will benefit greatly from more frequent testing.

Industries that require more frequent pen testing

Financial services (quarterly or monthly)

Understandably, amongst the most targeted businesses for cyberattacks are banks, fintech companies, and payment processors due to the highly sensitive financial and personal data they handle. Even the most minor vulnerability can lead to:

• Significant financial loss via payment fraud and card data breaches
• Account takeovers and credential stuffing attacks
• Insider threats and phishing campaigns

Healthcare & pharmaceuticals (quarterly or semi-annually)

The healthcare sector also handles highly sensitive data such as patient and medical records, making it a prime target for ransomware attacks and data theft. Security breaches can also affect service availability by disrupting critical patient care systems. Vulnerabilities in this sector can lead to:

• Ransomware targeting electronic health records (EHRs)
• Medical device vulnerabilities (IoT security risks)
• Insider threats and unauthorised data access

E-commerce & retail (quarterly)

Large online retailers often handle thousands (even millions) of daily transactions, making them a really lucrative target for hackers, stealing credit card details, exploiting payment systems, and executing large-scale fraud. Threats in this sector include:

• Payment gateway and checkout vulnerabilities
• Web application exploits (e.g. SQL injections, cross-site scripting)
• Magecart-style (card skimming) attacks that target online payment forms

Why quarterly or semi-annual pen testing is essential

Businesses in high-risk industries typically experience regular system updates, regulatory changes, and evolving cyber threats, meaning more frequent penetration tests can help detect security vulnerabilities before attackers are able to exploit them.

Frequent testing assists with identifying security weaknesses introduced by software updates, infrastructure changes, or application deployments. It can also help meet industry compliance requirements and avoid financial penalties, as well as strengthening customer trust through proactively securing sensitive data.

Monthly and continuous pen testing: when frequent testing is essential

As cyber threats are dynamic and evolve rapidly, organisations that handle sensitive financial data, critical infrastructure, and rapidly changing cloud environments, should not rely on annual or quarterly tests alone.

Businesses in finance, technology, cloud services, and critical infrastructure face persistent cyber threats that require real-time threat detection and regular security assessments. Additionally, compliance frameworks such as SOC2 Type II, PCI DSS Level 1, and ISO 27001 mandate ongoing or regular pen testing to ensure security controls remain effective.

Industries that require monthly or continuous penetration testing

Large enterprises & critical infrastructures

Examples include: telecoms, cloud providers, utilities, and government agencies.

Why? Large-scale IT environments and critical infrastructure are often targets for nation-state attacks, ransomware and insider threats.

FinTech startups & payment processors

Examples include: online banks, digital wallets, cryptocurrency exchanges.

Why? These businesses handle high-risk data, financial transactions, and often undergo rapid development cycles, making them prime targets for cyberattacks.

Businesses with compliance mandated frequent testing

Examples include: SaaS platforms, healthcare applications, financial services.

Why? Compliance frameworks like SOC 2 Type II and ISO 27001 require businesses to prove ongoing security measures, including pen testing.

Beyond scheduled penetration testing

Red teaming exercises

Instead of just identifying vulnerabilities, red teaming is a more realistic alternative to pen testing where real-world cyberattacks are simulated to test an organisation’s ability to detect, respond, and to mitigate attacks. Red teaming is ideal for those looking to test their incident response capabilities such as: enterprises, government agencies, and businesses with high-risk exposure.

Situational penetration testing

There are many key events or changes that can introduce new vulnerabilities to a business that require immediate penetration testing outside of the regular schedule:

• Major infrastructure changes – network upgrades, new servers, software deployments.
• Cloud migrations – moving data or applications to the cloud introduces new security risks.
• New office locations – expanding to new offices requires testing on-premise security and VPN configurations.
• Post-breach testing – after a security incident, penetration testing helps ensure that previously used attack vectors are closed.
• Implementation of a new payment system – payment processing changes require PCI DSS-compliant security assessments.
• Mergers & acquisitions (M&A) – integrating a new company’s IT infrastructure can expose unknown vulnerabilities.