Services for OEMs and EUMs TAC Services: essential identification for connected devices TAC Allocation The device identification system for all connected devices eSIM Services: supporting your eSIM investment GSMA eUICC Identity Scheme GSMA eSIM Discovery Fraud & Security Services: protect your devices against costly fraud GSMA Device Registry Empowering mobile operators and manufacturers to block stolen devices and reduce crime Network & Interconnect Services: make sure your devices work properly on networks GSMA Network Settings Exchange Give your subscribers a better experience, with services that run as smoothly as possible