IACS UR Z17 Compliance for Inspection Service Providers

Firms not employed by a classification society whose measurement, test or maintenance results a class surveyor relies on when making decisions affecting classification or statutory certification. Personnel are qualified under employer-based certification, so a contracted Level III can sign the written practice and administer examinations for the firm.

For NDT businesses the binding categories are thickness measurement on ships and mobile offshore units (excluding non-ESP ships under 500 gross tonnage and all fishing vessels), in-water survey by diver or ROV, ultrasonic tightness testing of closing appliances, remote inspection techniques, and tightness testing of membrane gas carrier barriers. UR Z17 sets the minimum requirements every IACS member society applies before it will accept a service supplier's results. The firm — not the individual technician — is approved. It must submit a company outline, personnel and equipment records, work procedures, training programmes, report formats and a quality manual; pass a document review; pass an on-site audit; and pass a practical demonstration of the actual service. Approval is granted per service category and per station: where a company owns several servicing stations, each is assessed and approved separately. Subcontractors performing the approved service must themselves meet Section 5. Every report issued must include a copy of the Certificate of Approval.

Source: IACS UR Z17 Rev.21, January 2025 — full 41-page text (Sections 1–9 plus Annex 1) read clause by clause from the ClassNK-hosted copy of the IACS requirement. The revision history in that text records Rev.19 and Rev.20 for uniform implementation by IACS Societies from 1 January 2026 and Rev.21 from 1 July 2026. Verified August 2026.

IACS UR Z17 at a glance — authority, scope and what it demands
ItemWhat appliesWhy it matters
AuthorityInternational Association of Classification Societies (IACS); applied and enforced by each IACS Member class societyThe body that issues, audits and can withdraw
Applies toFirms not employed by a classification society whose measurement, test or maintenance results a class surveyor relies on when making decisions affecting.Whether this binds your firm at all
Personnel certificationEmployer-based — the firm certifies its own, under a qualified Level IIIDecides whether an outsourced Level III can sign for you
RenewalRenewal or endorsement of the Certificate of Approval at intervals not exceeding five years by verification audit (6.2), or on expiry of the supplier's manufacturer approval where that applies, whichever comes first. For firms engaged in thickness measurements the interval must not exceed three years. Individual societies may impose shorter intervals and intermediate audits; failure to undergo a required intermediate audit is listed as grounds for cancellation under 8.2.4.Diarise from the certificate date, not from memory
Methods in scopeUT (ultrasonic thickness measurement), UT (ultrasonic tightness and leak testing), VT (close-up and remote visual), AE (acoustic emission), IRT (infrared/thermographic testing), MTEach method needs its own procedure and qualified personnel
IndustriesMarine classification and statutory survey, Shipyards and ship repair, Ship owners and managers, Mobile offshore units, LNG and membrane gas carriersWhere this regime shows up in contracts

Who does IACS UR Z17 apply to?

Firms not employed by a classification society whose measurement, test or maintenance results a class surveyor relies on when making decisions affecting classification or statutory certification. For NDT businesses the binding categories are thickness measurement on ships and mobile offshore units (excluding non-ESP ships under 500 gross tonnage and all fishing vessels), in-water survey by diver or ROV, ultrasonic tightness testing of closing appliances, remote inspection techniques, and tightness testing of membrane gas carrier barriers.

Can an outsourced Level III sign for IACS UR Z17 compliance?

Yes. IACS UR Z17 accepts employer-based certification, which places the obligation on the employer and allows a contracted Level III to write and sign the written practice, approve procedures and administer examinations. The Level III must be qualified in each method they sign for, and the employer still owns the records.

What documents does a IACS UR Z17 audit ask for?

Outline of company — organisation and management structure, including subsidiaries to be covered by the approval, List of nominated agents, subsidiaries and subcontractors, List of operators/technicians/inspectors documenting training, experience and qualifications to recognised national, international or industry standards, Description of the equipment used for the service, plus a guide for operators of that equipment, Training programmes for operators/technicians/inspectors. Auditors open records before they open manuals, because a manual describes intent while records show practice. The most common failure is a documented system that does not match what the technicians actually do.

How often is IACS UR Z17 renewed?

Renewal or endorsement of the Certificate of Approval at intervals not exceeding five years by verification audit (6.2), or on expiry of the supplier's manufacturer approval where that applies, whichever comes first. For firms engaged in thickness measurements the interval must not exceed three years. Individual societies may impose shorter intervals and intermediate audits; failure to undergo a required intermediate audit is listed as grounds for cancellation under 8.2.4. Firms that diarise renewal from the certificate date rather than from the last audit avoid the lapse that forces a full reapplication.

What are the most common IACS UR Z17 findings?

Operator or supervisor certificates on file do not cover the method or level the relevant Annex 1 category requires, No evidence of the minimum one year of tutored on-the-job training for operators required by 5.2.2, Equipment records missing maintenance history or the results of calibration and verification (5.2.5), Reports issued without a copy of the Certificate of Approval attached, which 5.2.11 requires. These recur because they are records problems rather than capability problems — the work is being done correctly and the evidence is not being kept.

Which NDT methods does IACS UR Z17 cover?

UT (ultrasonic thickness measurement), UT (ultrasonic tightness and leak testing), VT (close-up and remote visual), AE (acoustic emission), IRT (infrared/thermographic testing), MT, PT. Each method in scope needs its own approved procedure and personnel qualified in that specific method; a Level III qualified in ultrasonics cannot sign for radiography.

Personnel certification under IACS UR Z17

Employer-based, with a third-party overlay. Under 5.2.2 the supplier itself qualifies and trains its personnel to a recognised national, international or industry standard; operators need at least one year of tutored on-the-job training and supervisors at least two years' experience as an operator. For thickness measurement, Annex 1 gives EN 473 or ISO 9712 Level II for the supervisor and Level I for operators as examples of an acceptable standard. Annex 1 Section 15 names ASNT SNT-TC-1A explicitly alongside ISO 9712, but requires SNT-TC-1A holders to evidence that training was administered by an independent training body centrally certified to ASNT. An outsourced Level III can author and approve procedures and act as technical authority, but cannot replace the operator and supervisor certificates the audit inspects.

The audit sequence

Documents an auditor asks for

Findings firms get against IACS UR Z17

Related: the IACS UR Z17 overview, outsourced ASNT Level III cover, written practice development, NDT procedure development, a programme gap assessment, interim Level III cover.