This is the only way to ensure avoiding a bill for uninsured costs. Get written confirmation from your insurer about what is covered. If possible, provide full details of proposed treatment in writing, and ask for written authorisation to proceed. Return the original promptly.
Some insurers impose a time limit on claims.
It can be expensive and could become more so as you get older. You must weigh up the importance you attach to prompt treatment, greater choice and subjective factors such as greater comfort, privacy and probably better access to consultants. Insurance brokers specialising in PMI and other health policies. Advice on private and independent hospitals and nursing homes. Advice on NHS waiting lists.