TL;DR: Preparing for a cybersecurity audit doesn’t have to be overwhelming. Gather your network diagrams, security policies and access lists in advance, involve management and HR in addition to IT, and make sure the auditor has read-only access to your management consoles. Proper preparation shortens the process by days, saves costs, and produces a report you can start working on right away.
You have decided to have a cybersecurity audit performed. Smart, because it will give you a clear view of the vulnerabilities in your IT environment. But you may be wondering: what exactly are they going to do? What do we need to get ready? And what if they find all kinds of problems?
These are understandable questions. The good news: an audit is not an exam you can fail. It’s a health check for your IT environment, performed by a partner who stands beside you. With the right preparation, the process goes smoothly, you keep costs manageable and you get the most out of the results. This article provides a concrete checklist to prepare for your cybersecurity audit.
What happens during a cybersecurity audit?
A cybersecurity audit goes through four phases: intake and scoping, preparation, execution and reporting. For a medium-sized company with 50 to 250 employees, the full process typically takes two to four weeks, depending on the complexity of your infrastructure.
In the intake phase, the auditor defines the boundaries of the audit with you. Which systems, networks and processes will be examined? Which framework will be used as a measuring stick, for example CyberFundamentals (CyFun) or CIS18? This scoping conversation is crucial, because too broad a scope makes the audit unnecessarily expensive, while too narrow a scope leaves blind spots.
During the implementation phase, the auditor combines technical analysis (vulnerability scans, configuration reviews) with organizational review (interviews, process verification). The auditor works in the background and disrupts your daily operations as little as possible. According to Proximus research, one in three Belgian companies has already been affected by a substantial cybersecurity incident. The audit helps you discover whether your organization is prepared for such a scenario.
The reporting phase provides you with a risk matrix: an overview of all findings, ranked by likelihood and impact. In the process, you are given a concrete roadmap with priorities. Critical findings call for action within days, medium-risks within three to six months.
The documentation you should have ready
The quality of your preparation directly determines how smoothly the audit goes. Auditors work evidence-based: they don’t just test what you tell them, they want to see tangible evidence. An unprepared audit leads to 20% to 30% higher costs due to extra auditor hours.
Have these documents ready for the auditor:
Technical inventory: an up-to-date network diagram with VLAN segmentation, VPN gateways and cloud connections. In addition, a list of all servers, endpoints, mobile devices and network components with ownership. Also include a software inventory with version numbers and licensing information, including SaaS applications.
Security policies: your Information Security Policy, Acceptable Use Policy and access management procedures. The auditor looks specifically at the date of last revision and formal board approval. Important: Your backup policy should not only describe the schedules, but also include evidence of recent, successfully conducted recovery tests.
Incident response plan: including escalation lines, contact information for external partners and procedure for reporting incidents to the CCB.
Contracts with IT vendors: processor agreements, SLAs with security requirements, and any reports from previous audits or pen tests. The NIS2 legislation explicitly mandates the evaluation of supply chain cybersecurity, making it an increasing part of the audit.
Which stakeholders should be involved?
Preparing for a cybersecurity audit is not a task for IT alone. The modern audit approach, reinforced by NIS2 legislation, places responsibility with the entire organization. Therefore, involve the right people from the beginning.
Directors bear ultimate responsibility for risk management and must allocate budget and staff time. Under NIS2, directors are personally responsible for overseeing security measures. The IT manager facilitates technical access and explains network architecture. The HR department is needed to review on- and off-boarding processes, awareness training and clauses in employment contracts. And the DPO or compliance officer ensures the synergy between cybersecurity and GDPR.
A practical tip: plan a short kickoff meeting with all stakeholders in advance. That way everyone knows what is expected, and you avoid the auditor having to wait for information during implementation.
The five most common mistakes in an initial audit
Analysis of hundreds of audit projects at Belgian SMEs reveals five recurring pitfalls. Knowing them in advance will save you time and money.
1. Starting late to prepare. Collecting scattered documentation and updating network diagrams takes more time than you think. Count on at least two weeks of preparation. If you don’t start until the auditor is already scheduled, you will be paying auditor hours for work you could have done yourself.
2. Providing outdated documentation. A network schedule that does not reflect the migration to Microsoft 365 is a red flag. It undermines the credibility of your security management. Make sure all documents reflect the current situation. Do you have a Microsoft 365 environment? If so, make sure that configuration is documented as well.
3. Experiencing the audit as control. This is a psychological barrier that makes the audit less effective. If the IT team sees the auditor as a “checker,” it creates a defensive attitude that hinders transparency. Emphasize internally that the audit is a tool for risk reduction, not reckoning.
4. Misdefining the scope. Remember that mobile devices, home workstations and cloud environments are also part of the scope. A BYOD (Bring Your Own Device) environment that falls outside the audit may pose a critical security risk.
5. “Clean up” the IT environment before the audit. A common reflex, but exactly the wrong one. The audit should reflect the day-to-day, operational state. A temporary cleanup masks structural deficiencies that can be fatal during an incident.
Preparing your audit in the context of NIS2
The NIS2 legislation, effective since Oct. 18, 2024 in Belgium, changes the nature of the cybersecurity audit for SMEs. The law prescribes ten minimum security measures (Article 21) that are at the heart of the formal audit. Your preparation will be stronger if you know these measures.
The 10 categories include risk analysis and security policies, incident handling, business continuity, supply chain security, basic cyber hygiene and training, and multifactor authentication. The CyberFundamentals framework translates these requirements into concrete controls for each maturity level. With 34 controls, the Basic level already covers 82% of the most common attacks, making it the logical starting point for many SMEs.
A helpful first step: conduct a self-assessment beforehand with the CCB’s CyFun Self-Assessment Tool. This will give you an indication of your current maturity and where the biggest gaps are. That self-assessment is also valuable input for the auditor, as it shortens the analysis phase.
What does good preparation yield?
A well-prepared audit not only saves costs but also delivers a more valuable result. The final report includes a management summary with your risk position, a risk matrix with findings by category (critical, medium, low) and a concrete roadmap with priorities.
After the audit, establish an action plan with clear owners and deadlines for each finding. Also schedule a re-audit after several months to demonstrate that critical findings have been resolved.
Wondering what an audit costs? You can read more about prices and ROI in our article on cybersecurity audit costs. Flemish SMEs receive a 45% (small enterprise) or 35% (medium enterprise) subsidy on cybersecurity advice through the KMO-portefeuille. Through VLAIO cybersecurity improvement projects, the intervention can reach 50%.
Frequently asked questions about preparing for a cybersecurity audit
How long does a cybersecurity audit take for an SME?
For a medium-sized company with 50 to 250 employees, an audit takes an average of two to four weeks from intake to final report. The intensity for your IT team is highest in the first week, during preparation and the start of implementation.
Should I inform my employees about the audit?
Yes, but balanced. Inform staff that an audit is taking place so that suspicious activity (such as vulnerability scans) does not trigger unnecessary alarms. Do not specifically warn staff about upcoming phishing simulations, as this distorts the results.
What if our documentation is out of order?
That is exactly one of the things the audit exposes. You don’t have to have perfect documentation to get started. But the more you gather in advance, the shorter the audit will take and the lower the cost. Start with the basics: network diagram, software inventory and access policies.
Do I need an audit or a pen test?
It depends on your situation. An audit provides a broad overview of your security status. A pen test tests specific systems for technical vulnerabilities. Many organizations combine both: the audit as a strategic compass, the pen test as technical validation.
Can I get VLAIO funding for a cybersecurity audit?
Yes. Since February 1, 2026, the SME portfolio has been reserved exclusively for cybersecurity advice. Small enterprises receive 45% subsidy, medium-sized enterprises 35%, up to a maximum of €7,500 per year. Through the VLAIO cybersecurity improvement program, the intervention can even reach 50%.
How often should I have an audit performed?
For most SMEs, an annual audit is recommended. With substantial changes to your IT infrastructure (a cloud migration, an acquisition, a new application), an interim audit is prudent. Companies in high-risk sectors would do well to evaluate every six months.
Ready to prepare your audit?
A cybersecurity audit is an investment that pays for itself. You get clear visibility into your vulnerabilities, a concrete roadmap with priorities and the substantiation you need for NIS2 compliance. And with VLAIO grants, you pay up to half as much.
At Cyberplan, we start each project with a no-obligation scoping meeting. There we discuss your situation, determine the right scope together and explain what to expect. No jargon, just a clear plan.
