This circular letter introduces NSI Technical Bulletin No. 0054 which describes changes to the recently published amendment to BS EN 50131 – 1:2006. The main requirements introduced by the publication of the 2020 edition of BS EN 50131 1:2006 – A3 There are a few minor changes introduced in BS EN 50131 – 1:2006 – A3:2020. These changes relate to: published changes to associated product standards, for example the removal of the need for detection of significant reduction of range for some grade 4 detection devices; additional requirements to address introduction of remote access; and the introduction of the term ‘coercive principal’. This was introduced to address specific requirements of one or more European countries where tamper detection is not required during the unset state. Implementation dates At the time of writing this technical bulletin, amendment 3 of BS EN 50131 – 1:2006 was not called up in the current edition of PD 6662. The need for compliance with amendment 3 will coincide with the adoption of a future edition of PD 6662. PD 6662 will be revised in line with the BSI update schedule but currently there is no scheduled date to start a revision or update. How do I obtain a copy of BS EN 50131 – 1:2006 – A3:2020? BS EN 50131 – 1:2006 – A3:2020 is available as an outright individual purchase directly from the BSI or at a discounted price 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.