ComparisonInternal, external, or third-party audit?
Internal, external, or third-party audit?
The right format for your context.
Three ways to audit your application security. Internal is free but biased. A freelancer is flexible but uneven. A specialized firm brings independence and method. Here is how to choose.
Detailed comparison
| Criterion | Internal audit | Security freelancer | Specialized firm |
|---|---|---|---|
| Independence | Low (same teams, same biases) | Variable (depends on the freelancer) | Strong (outside perspective, formalized method) |
| Security expertise | Limited unless a dedicated team exists | Variable (check the track record) | Specialized (it is the core business) |
| Cost | Internal time (often underestimated) | EUR 500 to 5,000 depending on scope | EUR 1,900 to 10,000 depending on format |
| Availability | Immediate but often pushed back | Depends on freelancer schedule | Plannable, contractual commitment |
| Formalized method | Rare (no standardized framework) | Variable | Yes (process, phases, defined deliverables) |
| Actionable report | Internal notes, rarely formalized | Variable quality and format | Structured report, reproducible evidence |
| Regulatory value | Low (regulators see the lack of independence) | Acceptable if properly documented | Strong (independent due-diligence evidence) |
| Ongoing monitoring | Possible but rarely structured | Depends on the relationship | Recurring monitoring plans available |
| Confidentiality | Internal by definition | NDA required | NDA and standard contractual framework |
| Confirmation bias | High (the team audits its own work) | Low | Very low |
Internal audit works if...
- You have a dedicated security team with time allocated
- You want a quick first pass before commissioning an external audit
- The scope is very narrow (one feature, one endpoint)
- You are preparing a spec for an external firm
A specialized firm works if...
- You need an independent perspective and a formal report
- You need to demonstrate due diligence (GDPR, insurance, investor)
- Your team lacks application security expertise
- You want a structured process with actionable deliverables
- You are looking for ongoing monitoring (audit + recurring checks)