ISO 27001 internal audit: outsource or do it yourself?
Short answer: doing it yourself looks cheaper, but because of internal hours, organisational blind spots and the objectivity requirement it often costs more than outsourcing. The standard also prohibits you from auditing your own work. For most organisations, hiring an independent auditor is both more cost-effective and more objective. Below we compare both options and show what to look for when choosing an audit partner.
Comparison in a single table
| Aspect | Do it yourself | Outsource |
|---|---|---|
| Objectivity | Difficult: you may not assess your own work | High: an independent perspective |
| Cost (indicative) | Seemingly low, but internal hours + risk often add up | Clear in advance, per project |
| Time from internal team | High | Low |
| Likelihood of passing the certification audit | Variable | Higher (a fresh pair of eyes sharpens results) |
The market indications mentioned vary by provider and scope; always request a tailored quote.
Why objectivity weighs the heaviest
Certification bodies require the internal audit to be impartial: the auditor may not assess their own work or process. In small teams that separation is hard to arrange. A hired Lead Auditor solves this and prevents organisational blind spots.
When does doing it yourself make sense?
Do you have a mature ISMS, a separate, qualified internal audit function that is independent of the process owners, and enough capacity? Then you can carry out (part of) the internal audits yourself. Many organisations opt for a mix: the routine in-house, and the annual independent assessment and the pre-audit externally.
What should you look for when choosing an audit partner?
- Demonstrable audit experience and qualifications (ISO 19011, Lead Auditor).
- Independence — does not assess its own advisory work.
- Sector and context knowledge — not a generic approach.
- Clear reporting that both management and technical teams understand.
- Transparency about the approach and planning — be alert to anyone promising "certification in a few weeks" without analysis.
Our advice
For most SMEs, outsourcing the internal audit and pre-audit is the wisest choice: more objective, less of a burden and a higher likelihood of success. Take a look at our internal audit, the ISO 27001 audit and hiring a Lead Auditor.
ISO 19011 — guidelines for auditing (official source).
Frequently asked questions
Short, direct answers — written for people and for AI search features alike.
On paper it often looks that way, but in practice it disappoints. Internal hours, a lack of routine, organisational blind spots and the risk of nonconformities during the certification audit regularly make doing it yourself more expensive than outsourcing. On top of that, the internal auditor may not assess their own work, which limits how they can be deployed.
You are not required to outsource, but you are allowed to, and it improves objectivity. The standard only requires that the internal audit is carried out impartially by someone who does not assess their own work. An independent external auditor meets that requirement by definition.
That varies by provider, scope and the size of the organisation. Market indications vary widely; rather than quote a guide price that does not fit your situation, we make a tailored estimate during a no-obligation audit scan.
Look for demonstrable audit experience and qualifications (ISO 19011), genuine independence, sector and context knowledge, clear reporting for both management and technical teams, and transparency about the approach. Be wary of parties that promise quick certification without thorough analysis.
Want to know whether you are audit-ready?
Book a no-obligation audit scan and find out within a single conversation where you stand and what the next step is.
