Why quotes vary more than for older standards
Certification bodies price audits in man-days, and man-day calculation for a young standard is still settling: auditor availability with genuine AI competence is scarce, accreditation for the standard is still rolling out across bodies, and scope complexity differs enormously between "we use a vendor's model in one feature" and "we train and serve foundation models". Expect a wider quote spread than you would see for ISO 9001 or 27001, and treat that spread as information: a body that cannot explain its man-day calculation for your AI footprint is guessing.
The cost buckets
- Certification body fees. Driven by man-days, which scale with the number and risk of AI systems in scope, your role (developer, provider, user), locations, and headcount involved in the AIMS.
- Internal implementation. The dominant cost: AI inventory, risk and impact assessments, lifecycle and data controls, monitoring, internal audit, and management review. Organizations with an existing ISO 27001 ISMS typically add 30 to 50 percent effort on top of it rather than starting from zero.
- Optional consulting and tooling. AI governance consulting is priced at a premium while expertise is scarce; tooling for model inventory, evaluation, and monitoring helps cloud-native teams but certifies nothing by itself.
What moves your quote
Upward: many AI systems in scope, high-impact use cases (hiring, credit, health, safety), model development activities rather than pure deployment, multiple entities or sites, and regulated customers whose requirements enter your interested-party analysis. Downward: a precise scope around the AI products your customers actually buy, a functioning ISO 27001 foundation the AIMS integrates with, and clean evidence habits that shorten audit sampling.
Comparing bidders fairly
Ask each certification body: the accreditation behind their ISO 42001 program, their auditors' actual AI competence (audits led by someone who has never seen a model lifecycle produce shallow certificates that sophisticated buyers discount), man-days per visit across the full three-year cycle, and reporting turnaround. The cheapest certificate that fails your customer's due diligence is the most expensive document you can buy.