This category covers the organisation's customer base itself and the relationships built with it — who your customers are, how long they've been with you, and the trust and goodwill accumulated over time. It's distinct from Customer systems and data, which covers the data and systems used to serve customers, not the relationship itself.

A breach or service disruption doesn't just cost you data or uptime — it can cost you customers who decide to take their business elsewhere. For SMEs with a concentrated customer base (a handful of large clients making up most of revenue), the loss of even one relationship can be a bigger impact than the direct cost of the incident itself.