NSI Technical Bulletin No. 0020 provides guidance on implementing BS 8484:2011, which supersedes the previous standard BS 8484:2009, for the provision of lone worker device (LWD) services. The bulletin outlines the mandatory compliance requirements for NSI approval, including the necessity for companies to address any Improvement Needs by September 2012, and details significant changes in the new standard, such as enhanced data security measures and the need for a documented data handling policy. It also emphasizes that all organizations providing LWD services must adhere to the new standards to maintain their NSI approval.