Best ISO 27001 Auditors: Options From a 29-Firm Pool
ISO 27001 certification must come from an accredited certification body. Our ordinary-provider pool contains 29 firms listed for ISO 27001; up to 10 total options are shown. That tag does not establish completed work, certification-body status, or accreditation.
ISO 27001 service and provider options (10 shown)
AuditNex is listed first as our own featured quote-comparison service, not an auditor or an independently earned auditor ranking. Auditsuisse Assurance is a featured general option when active; its placement does not establish suitability for this page's framework, industry, platform or location. Other firms retain the directory's stated ordering. Featured placement does not change verification, reviews or pricing data. Directory firms retain their evidence-based order after the featured entries. Select up to three directory firms to compare them side by side.
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Compare the same scope, timing and final fees. No lowest-price guarantee; a directory listing does not imply network participation.
Auditsuisse Assurance
Contact Auditsuisse Assurance to confirm its services, current qualifications, scope, availability and fees.
Featured inclusion is not confirmation of a particular framework, industry, platform relationship or local presence. Credentials and suitability must be checked directly.
Official website: AuditSuisse.com
3. A-LIGN
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Secureframe, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
4. Aprio
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
5. BARR Advisory
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Secureframe, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
6. Insight Assurance
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Secureframe, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
7. Prescient Assurance
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Secureframe, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
8. Schellman
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Secureframe, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
9. Sensiba
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- ✓ GRC platform listings: Drata, Vanta; integration not established by the tag
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
10. 360 Advanced
Unverified · public records- – Price band: not yet verified
- – Typical timeline: not yet verified
- – GRC platform relationship: unknown
- ✓ Listed as a CPA firm; confirm current licensure and attestation eligibility
- – No verified client reviews yet
Compare services and providers at a glance
| # | Service / provider | Price band | Timeline | GRC platforms | Verified reviews | Status |
|---|---|---|---|---|---|---|
| 1 | AuditNex — compare quotes from multiple auditors Compare audit quotes | Quoted for your scope | Confirm with matched auditors | Not applicable | Not applicable | Quote-comparison service, not an auditor |
| 2 | Auditsuisse Assurance | Not yet verified | Not yet verified | Not yet verified | Not yet verified | Featured general provider; scope and availability must be confirmed |
| 3 | A-LIGN | Not yet verified | Not yet verified | Drata, Secureframe, Vanta | No verified reviews yet | Unverified |
| 4 | Aprio | Not yet verified | Not yet verified | Drata, Vanta | No verified reviews yet | Unverified |
| 5 | BARR Advisory | Not yet verified | Not yet verified | Drata, Secureframe, Vanta | No verified reviews yet | Unverified |
| 6 | Insight Assurance | Not yet verified | Not yet verified | Drata, Secureframe, Vanta | No verified reviews yet | Unverified |
| 7 | Prescient Assurance | Not yet verified | Not yet verified | Drata, Secureframe, Vanta | No verified reviews yet | Unverified |
| 8 | Schellman | Not yet verified | Not yet verified | Drata, Secureframe, Vanta | No verified reviews yet | Unverified |
| 9 | Sensiba | Not yet verified | Not yet verified | Drata, Vanta | No verified reviews yet | Unverified |
| 10 | 360 Advanced | Not yet verified | Not yet verified | Not yet verified | No verified reviews yet | Unverified |
What to check before hiring an ISO 27001 auditor
Accredited certification body
Only an accredited certification body (e.g. ANAB or UKAS accredited) can issue the ISO 27001 certificate. Confirm accreditation and scope.
Stage 1 + Stage 2 plan
A credible auditor lays out both stages, the surveillance audit cadence, and the three-year recertification cycle up front.
SOC 2 crossover
If you also need SOC 2, a firm that handles both can reuse evidence and cut total audit effort significantly.
Sector experience
ISMS scoping differs a lot between SaaS, fintech, and hardware companies — ask for relevant certificates issued.
Frequently asked questions
Who can issue an ISO 27001 certificate?
Only an accredited certification body can issue an ISO 27001 certificate. Many audit firms also offer readiness assessments and internal audits, but the certificate itself must come from an accredited body — always confirm accreditation and its scope.
Can one firm do both my SOC 2 and ISO 27001?
Often yes. Many CPA firms with ISO 27001 practices (or certification-body partnerships) can run both engagements and reuse overlapping evidence, which typically lowers total cost and audit fatigue.
How were these ISO 27001 firms ranked?
AuditNex's quote-comparison service and the disclosed general provider appear first. Other firms are ordered by verification status, profile completeness, and verified client reviews; the methodology page documents those signals.
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