The Complete Guide to ISO 27001 Audits for Startups and Scaleups

Everything you need to know about surviving (and thriving through) ISO 27001 audits - from preparation through certification and beyond

Getting through an ISO 27001 audit can feel like sitting your A-levels all over again, except this time you're being graded on whether your company can actually keep customer data safe. For startups and scaleups juggling limited resources and ambitious growth targets, the audit process often feels like an intimidating black box.

This guide demystifies the entire ISO 27001 audit journey, giving you practical insights into what actually happens during each stage, how to prepare your team, and how to turn audits from a necessary evil into a competitive advantage.


Understanding the ISO 27001 Audit Landscape

ISO 27001 audits aren't a one-and-done affair - they're a structured journey that spans three years and involves multiple checkpoints. Think of it as an ongoing relationship with your certification body rather than a single exam.

Unlike other compliance frameworks that focus purely on ticking boxes, ISO 27001 audits dig into whether your security measures actually work in practice. Auditors don't just want to see your policies gathering digital dust in a SharePoint folder - they want evidence that your team lives and breathes information security.

The Four Types of ISO 27001 Audits

1.

Stage 1 Audit: The Documentation Review

Your auditor plays detective with your paperwork, checking whether you've got all the required policies, procedures, and evidence in place. Think of it as a comprehensive health check before the real test begins.


2.

Stage 2 Audit: The Implementation Test

This is where rubber meets road. Auditors verify that your security controls actually work, your staff know what they're doing, and your ISMS isn't just impressive-looking documentation.

Annual Surveillance Audits Yearly check-ins to ensure you haven't let standards slip. These shorter audits focus on specific areas and any previous non-conformities.

Recertification Audit (Year 3) A comprehensive review similar to Stage 2 that determines whether you've earned another three-year certificate.

Stage 1 Audit: Getting Your Paperwork Sorted

The Stage 1 audit typically lasts 1-2 days and focuses entirely on documentation. Your auditor essentially becomes a very thorough management consultant, examining whether your ISMS foundation is solid enough to support implementation testing.

What Auditors Actually Examine

During Stage 1, expect your auditor to meticulously review:

  • ISMS Scope Definition: Is your scope clearly defined with justified inclusions and exclusions? Auditors hate vague scope statements that look like they were written by a committee of lawyers.

  • Information Security Policy: Is it approved, current, and properly communicated? Bonus points if employees actually know it exists.

  • Risk Assessment Methodology: Does your approach meet ISO 27001 requirements? Your methodology needs to be more sophisticated than "we asked Dave from IT what could go wrong."

  • Statement of Applicability (SoA): Are control selections justified and aligned with your risk assessment? This document needs to tell a coherent story, not read like a random shopping list.

  • Mandatory Documentation: All required policies, procedures, and records. The auditor will check you've got everything ISO 27001 demands, properly approved and version-controlled.

Stage 1 Outcomes: The Verdict

Within about a week, you'll receive one of three outcomes:

  1. Ready for Stage 2: Your documentation is complete and you can proceed

  2. Ready with areas of concern: There are some issues that could become non-conformities in Stage 2 (NORMAL!)

  3. Additional work required: Significant gaps need addressing before Stage 2 can proceed

If you're not ready, don't panic. Some organisations need to address findings before moving forward - it's normal and expected. Better to fix issues now than face major non-conformities during Stage 2.

Stage 2 Audit: The Real McCoy

Stage 2 is where your ISMS gets properly tested. This audit lasts 2-6 days depending on company size and evaluates whether your security controls actually work in practice. Auditors aren't just checking boxes - they're assessing if your security programme is operational and effective.

What to Expect During Stage 2

Your auditor will conduct a thorough examination of your ISMS in action:

  • Conduct on-site assessments: Verify that security controls are active and working

  • Interview employees at all levels: Test awareness and practical application

  • Review evidence of implementation: Audit logs, incident records, training records

  • Test security controls: Sample implementations across your Statement of Applicability

  • Examine your ISMS in action: Risk management, incident response, corrective actions

The Statistical Sampling Approach

Auditors use statistical sampling rather than checking every single device or process. If you have 100 laptops that need encryption, they'll randomly select a handful to verify. This makes the audit feasible while still providing confidence in your overall implementation.

Stage 2 Outcomes

At the closing meeting, you'll receive one of three outcomes:

  1. Recommendation to certify: No issues found (rare but possible)

  2. Certification with corrective actions: Minor non-conformities requiring a corrective action plan

  3. No recommendation: Major non-conformities must be resolved before certification

Common Questions (And How Not to Mess Them Up)

Security Awareness

What would you do if you spotted a security incident?

  • Good answer: "I'd report it immediately through our incident management system and notify [security contact]"

  • Bad answer: "Delete everything and run for the hills"

Access Control

How do you handle access to systems?

  • Good answer: "Access is requested through our ticketing system and requires manager approval"

  • Bad answer: "I just ask Dave for his password"

Information Handling

How do you share sensitive information with clients?

  • Good answer: "We use our approved secure file sharing system and classify information according to our data classification policy"

  • Bad answer: "WhatsApp usually, or carrier pigeon for the really secret stuff"

Quick Fire Do's and Don'ts

Do:

  • Review recent security incidents and how they were handled

  • Know your main security contacts

  • Understand basic security procedures for your role

  • Keep your workspace tidy & secure during the audit (yes, they might ask about people overhearing conversations)

  • Take a breath before answering questions

Don't:

  • Try to memorise policies word-for-word

  • Make up processes on the spot - you could be asked for evidence

  • Volunteer unnecessary information

  • Panic if you don't know something

  • Argue with the auditor - leave that to the primary person overseeing the audit on your side!

If You Get Stuck

Remember these lifeline phrases:

  • "Let me refer to our documentation for the exact process..."

  • "That's handled by [team/person], but I know how to contact them if needed"

  • "I'd follow our documented procedure for that, which I can show you"

  • "I'm not certain about that specific detail, but I know where to find the information"

The Night Before Checklist

Review your role's security responsibilities

  • Know where to find relevant documentation

  • Clean your desk (seriously, do it)

  • Get some sleep (auditors can smell fear)

  • Remember: You've got this!

Final Thoughts

Remember, the auditor is checking our security system, not writing your performance review. They want to see that we're taking security seriously and have practical, working processes in place. You don't need to be perfect - you just need to show that you understand your part in keeping our information secure.

And if all else fails, remember: No auditor has ever actually turned someone into stone with their gaze. We're pretty sure about that. Almost entirely sure.

Good luck! (Though you won't need it because you're going to nail this)