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ISO 45001:2018 Migration Guidance for Clients

Migration guidance plan

NQA considers ISO 45001:2018 to be a significant development primarily due to changes in structure, and the introduction of additional concepts and themes.

It is our goal to ensure that we perform value added audits that establish an organization’s level of conformity to the standard and in doing so, help our clients understand both the intent and the philosophy behind the changes.

NQA’s philosophy is to maintain a simplistic migration approach that is easy for our clients to comprehend and apply. 

Our goal is to provide you with the guidance and tools to make the migration from OHSAS 18001:2007 to ISO 45001:2018 as smooth and cost-free as possible. 

The overall allowable migration period was originally three years; but that migration period has since been extended by six months due to the COVID pandemic. As such, the current migration period is from March 2018 through September 30, 2021.


Step 1: Migration guidelines - ISO 45001:2018

  1. The International Accreditation Forum (IAF) has stated that organizations will have 3 years from the date of the standards publication to migrate their OHSMS to become compliant to the new standard.

  2. All current existing certificates to OHSAS 18001:2007 will expire three years after release and publication of ISO 45001:2018.

  3. Migration from OHSAS 18001:2007 to ISO 45001:2018 may be accomplished during a single visit. A minimum of one day additional time shall be added to the duration to effectively evaluate the changes and effectiveness of implementation. Based on IAF MD-21:2018 – issue 1.

  4. If a client’s OHSAS 18001:2007 certificate expires before they are able to fully migrate to the ISO 45001:2018 standard, they may be re-registered to OHSAS 18001:2007 (subject to a cut-off period to allow for subsequent migration).

The expiration date of this re-registered certificate will be within the three year anniversary of the release of ISO 45001:2018.

  1. A new certificate to the 2018 version will be issued when it can be satisfactorily shown that a client has fully met the requirements of the new standard. As is the current practice, all major non-conformities must be formally closed out and corrective actions for any minor non-conformances must be received and accepted by NQA, prior to issuance of a certificate.

Prior to the Migration Audit being undertaken, clients are required to complete the NQA ISO 45001:2018 Gap Analysis Document.  Clients are also encouraged to complete an internal audit and management review against the new standard, as this exercise serves both to ensure that all requirements have been addressed in the management system and to provide easy reference to these requirements during the migration audit. As a minimum, the client must have completed a formal gap analysis using the document mentioned above and reviewed the output with Top Management at management review or an equivalent mechanism.

Step 2: Your migration process

Based on the three-year migration timeline, we have developed the following migration process for organizations that currently have a registered OHSAS 18001:2007 system with NQA:


  • Migrations will be conducted at the time of annual surveillance or recertification audit.

  • Additional mandatory time will be added to the audit duration in order to allow the completion of a full and effective migration assessment against the new standard requirements.  

  • The additional time will be a minimum of one day. Additional time will be determined according to unique criteria of the organization. This will be determined by NQA. To find out your specific migration audit duration please talk to a member of the NQA team.  

  • If successful, NQA will issue a new certificate with the valid until date (VUD):

    • At a surveillance audit - this will reflect the previous certificate.

    • At a re-certification audit – this will reset the three year certification cycle

    • In the circumstance where the three year certification cycle has been restricted by the end of the migration period, and the migration has taken place during a surveillance audit, the VUD date will be reset to three years from the date of the previous reassessment or initial certificate VUD.

Please note: At the point of scheduling your migration audit you will be informed of the additional days required and therefore the audit duration and cost. This will be determined by NQA and applies to all organizations.

Step 3: Inform NQA

We need to know when you wish to migrate from OHSAS 18001:2007 to ISO 45001:2018. Please help us to plan your forthcoming migration audit by informing us of your decision. 

Step 4: Gap analysis tool

The NQA ISO 45001:2018 Gap Analysis Document provides a simple framework for evaluating your OHSMS against the requirements of ISO 45001:2018. The document highlights:

  • The new concepts introduced in ISO 45001:2018 and the related clauses, processes and functional activities

  • The new and amended clauses between OHSAS 18001:2007 and ISO 45001:2018

Please complete each table by recording the evidence acquired from one full internal audit against the requirements of ISO 45001:2018. Complete all sections prior to your migration assessment and ensure it is available for your assessor at the opening meeting.


If you have any questions or just want to speak to someone regarding your migration please contact us.

NQA support

NQA are here to help and support our clients, both current and future, and we have plenty of materials, guidance documents and information to help you on your journey.

  • Click here for information on ISO 45001

  • Click here to download an ISO 45001 Implementation Guide

  • Click here to see our ISO 45001 Migration Webinar

H&S Toolkit

ISO 45001 FAQs

ISO 45001 Migration Timeline

ISO 45001:2018 Migration Video

ISO 45001 Gap Guide

ISO 45001 Implementation Guide

Download Certification Logos

Annex SL Comparison Tool

Gap Analysis