The average cost of a penetration test usually ranges between £3,000 and £10,000 for small to medium-sized businesses. For larger organisations or complex environments, prices can reach £20,000 or more.
Penetration testing, often called pen testing, helps identify weaknesses in networks, websites, or infrastructure before attackers can exploit them.
The cost of this service may vary on the size of the company and also the technology they run, with testing used for web applications, networks, clouds, AI penetration testing and more.
What is The Average Cost of Penetration Testing?
| Type of Organisation / Test | Typical Cost Range (GBP) | Example Scope |
|---|---|---|
| Small business website test | £2,500 – £4,000 | Single web app or small external network |
| Medium-sized company penetration test | £5,000 – £10,000 | Multiple systems, web apps, and internal network |
| Large enterprise or complex environment | £10,000 – £20,000+ | Cloud, hybrid systems, and advanced testing |
| Red teaming | £20,000 – £50,000+ | Full-scale simulated attack with multiple testers |
What Are The Factors That Affect The Cost of Penetration Testing?
The scope of the test is a key factor in determining the pricing:
Limited vs full test – A limited test that covers only one website costs less than a full assessment of your internal network, servers, and cloud setup.
External vs internal tests – External tests that target internet-facing systems are often less expensive than internal tests, which require more access and deeper analysis.
Size and complexity – A small business with a few devices and a single office will be simpler to test than a large company with multiple locations and hundreds of users. The more systems a tester must evaluate, the more time and expertise are required, which increases the cost.
Compliance requirements – If you require industry level assurance such as PCI DSS, ISO 27001, or Cyber Essentials Plus can increase the price, since these require formal documentation and detailed reports.
Types of Penetration Testing and Pricing in the UK
| Type of Penetration Testing | Typical Cost Range (GBP) | Description |
|---|---|---|
| External network testing | £3,000 – £6,000 | Focuses on public-facing systems like websites and firewalls |
| Internal network testing | £5,000 – £12,000 | Examines what could happen if an attacker gained internal access |
| Web application pen testing | £2,500 – £8,000 | Tests websites or online apps for vulnerabilities |
| Cloud penetration testing | £4,000 – £10,000 | Targets systems hosted on platforms such as AWS or Azure |
| Red team engagement | £20,000+ | Simulates real-world attack scenarios over several weeks |
How Long Does Penetration Testing Take?
Smaller tests can take just a few days, while larger, more detailed assessments may take weeks. The number of testers involved also matters.
According to a 2024 report from the UK Cyber Security Council, the average penetration test lasts about seven working days, and around 60% of companies use at least two testers for each project.
The time spent not only covers testing but also includes analysis, reporting, and recommendations.
Is Cheap Penetration Testing Better?
Choosing the cheapest penetration testing provider might seem like a good way to save money, but it can often lead to poor results.
Low-cost testers might rush the process, miss vulnerabilities, or provide limited guidance on how to fix issues.
According to TechUK, 37% of UK businesses that chose budget penetration testing later discovered serious unreported vulnerabilities in follow-up assessments. Investing in skilled, certified testers ensures your systems are properly evaluated and your report delivers real value.
Should You Do One-Off Pen Tests or Ongoing?
Penetration testing isn’t something to do just once. Cyber threats change quickly, and new vulnerabilities appear regularly. Experts recommend testing at least once a year or after any major change to your systems.
Many companies offer ongoing contracts or reduced rates for regular testing, which can help spread costs over time. Treating penetration testing as part of your annual cyber security budget keeps your defences up to date and predictable.
What To Expect From a Pen Test
A penetration test is a planned, controlled simulation of a cyber attack carried out by skilled security professionals. The goal is to find weaknesses in your systems before a real attacker does.
When you book a penetration test, the process usually begins with a discussion between you and the testing team. This helps define the scope of the work, identify the systems to be tested, and agree on boundaries. The testers will also confirm any legal permissions, as they will be actively probing your systems in ways that could resemble a real attack.
Once the test begins, the penetration testers will use a combination of automated tools and manual techniques to identify vulnerabilities. They might look for weaknesses in network configurations, outdated software, or poorly secured applications.
The process often includes several stages: reconnaissance, where testers gather information about your systems; scanning, where they identify open ports or potential weaknesses; exploitation, where they attempt to gain access; and post-exploitation, where they determine how far an attacker could go if a breach occurred.
During the test, you might notice increased network activity or system logs showing unusual behaviour. However, a reputable testing team will coordinate carefully to minimise disruption. Many companies choose to have the test carried out outside of business hours or in a staged environment to reduce risk.
After the test, the testers will compile a detailed report explaining their findings. This document outlines the vulnerabilities discovered, how they were exploited, and what impact they could have on your business. It also includes clear, practical recommendations for fixing the issues. A follow-up meeting is often held to walk through the results, answer questions, and prioritise next steps.