How Much Does a Cyber Security Audit Cost in the UK?

Most pages answering this question say "it depends" and stop there. That is not useful when you are trying to put a number in a budget. Here is what actually drives the price, and what you should expect for the money.

What Drives the Cost

Audit pricing is essentially days of senior time, so the cost tracks how much there is to look at and how much evidence needs verifying:

• Number of users: the single biggest factor. Twenty users is a different exercise to two hundred.
• Number of sites and networks: one office with cloud services is simpler than four sites with on-premise servers.
• Systems in scope: Microsoft 365 alone versus 365 plus servers, line-of-business applications, cloud infrastructure and OT.
• Framework alignment: a general review is lighter than one mapped formally to ISO 27001 or the NCSC CAF, because mapping and evidence expectations add work.
• Technical testing depth: whether external vulnerability scanning and configuration review are included, and how much validation is expected.
• Evidence maturity: organisations with nothing documented take longer, because the auditor is reconstructing the picture as well as assessing it.
• Reporting audience: a working findings list is quicker to produce than a board-ready report plus a client-facing summary.

What a Typical SME Engagement Looks Like

For a UK business of roughly 20 to 100 users running mostly cloud services, an audit is usually a matter of days rather than weeks. In practice that means a scoping call, a period of evidence gathering and technical review, then a report and a walkthrough session.

Larger, multi-site or heavily regulated environments scale up from there, and formal framework-aligned work with detailed evidence mapping sits at the higher end. Anyone quoting a firm figure before understanding user count, systems in scope and the reason for the audit is guessing, and you should treat the number accordingly.

We do not publish a fixed audit price for the same reason we note it on our pricing page: consultancy is scoped and quoted per engagement, unlike IT support which works well on a per-user basis.

What Should Always Be Included

Whatever you pay, these should be in scope rather than sold as extras:

• A scoping conversation before any quote is issued.
• Review across identity, endpoints, email, network, data and process, not just a scan.
• A written report in plain English, with risk ratings that reflect your business rather than generic severity scores.
• A prioritised action plan, ordered by impact and effort, that someone could actually work through.
• A walkthrough session where you can ask questions and challenge findings.

Watch For These Cost Traps

• Scan-and-invoice: an automated vulnerability scan exported straight to PDF is not an audit. It is a component of one.
• Findings without prioritisation: a 90-item flat list transfers all the hard thinking back to you.
• Audits that exist to sell products: if every finding resolves to the auditor's preferred licence, the incentives are wrong.
• Retesting priced as a surprise: ask at the outset what it costs to verify fixes.
• Certification confusion: an audit is not certification. Cyber Essentials and ISO 27001 carry their own separate assessment and certification body fees.

Is It Worth It?

The comparison worth making is not audit cost versus zero. It is audit cost versus the cost of finding out the hard way. Incident recovery for a small business routinely runs into weeks of disruption alongside the direct costs, which we cover in the real cost of a data breach.

There is also a commercial return that gets overlooked. Audit output feeds client security questionnaires, insurer underwriting questions and certification preparation, all of which you would otherwise be assembling from scratch under time pressure.

How to Get an Accurate Number

Before asking for quotes, have these ready: user count, number of sites, whether you run on-premise servers, which cloud platforms you use, whether a specific framework or client requirement is driving this, and your deadline. With those six answers, any competent provider can scope properly and quote within a day or two.

To get a sense of your position first, run the free cyber health check, then get in touch for a scoped quote. Details of what the engagement covers are on our cyber security audit services page.