Managed Security Services - Office 365

As part of the ongoing digital transformation in NS&I, we have started to introduce new modern digital services for our staff including Microsoft 365 (M365, contract Ref# 22-D-05). This will bring material business benefits in efficiency and collaboration within our business as well as across Government and with third-party partners. As M365 is an externally hosted, cloud-based service there is a requirement for the M365 "Tenant" to be monitored by a security operations centre (SOC) which will identify any malicious activity, indicators of compromise and investigate any activity of this nature. When the activity to establish this service began in May 2023, the original design intent was for security monitoring to be provided by either Atos (as incumbent) or IBM (as incoming supplier of the new NS&I integration CSMS platform.) However, following advice from the NS&I Enterprise Design Authority (EDA) it was agreed to keep the NS&I Corporate functions and new retail platforms physically and commercially separate at this time. It is best practice to maintain independence of the SOC from the M365 supplier.