© 2009 - 2023 Security Industry United (SIU). All rights reserved. Security Industry United and SIU are the respective trademarks of the Security Industry Union Ltd. Registered office: 308 Trelawney Avenue, Langley, Slough SL3 7UB. Registered in England & Wales No. 7051660. SIU is not an insurance broker, underwriter, or a trade union. SIU member benefits are discretionary. Our preferred solicitors are regulated by the Solicitors Regulation Authority and barristers regulated by The Bar Standards Board. Executive Director Mr. Tolga Kavak.