This circular letter introduces NSI Technical Bulletin No. 0055 which describes the recently published BS 8406:2020. The main requirements introduced by the publication of the 2020 edition of BS 8406. The main reason for the change and introduction of this new edition is to bring the Event Stewarding standard in line with the new structure for service standards underneath the overarching BS 10800 standard for the Provision of security services. Companies wishing to hold approval to BS 8406:2020 must hold approval to BS 10800 as the overarching standard. Each Security services sector standard will be adapted and modified by the BSI to follow the new structure in due course. Implementation timescale for applicant companies: New applicant companies to NSI Guarding Gold and Silver schemes will be audited against BS 8406:2020 with immediate effect and any Improvement Needs recorded against clauses of the Standard will have to be satisfactorily addressed before approval can be granted. Implementation timescale for existing approved companies: NSI approved companies will need to be compliant with BS 8406:2020 by the 31st March 2021 after which a non-compliance will have an improvement need recorded against clauses of the Standard and these will have to be satisfactorily addressed before approval can be granted. How do I obtain a copy of BS 8406:2020? BS 8406:2020 is available as an outright individual purchase directly from the BSI or at a discounted rate from the NSI or, alternatively, as a download via the NSI approved company Standards on Subscription service. Questions or queries? If you have any questions or queries regarding the implementation of the change, please do not hesitate to contact me.