The short answerTrustees have a duty to manage charity reserves prudently — which, for longer-term reserves, can mean investing rather than leaving cash to erode against inflation. A regulated adviser helps you invest in line with your reserves and investment policies and trustees' legal duties.
Why it matters
Holding years of reserves in cash can be as much a risk as holding too little — inflation erodes them and trustees may be failing their duty to manage funds well. Regulated, sector-aware investment advice turns idle reserves into a managed asset.