You need at least 0.75 million Special Drawing Rights (about £0.75million cover of public liability insurance
You only need drone insurance when you are flying commercially, however, you need to make sure that you have the right cover and the right amount of cover.
Firstly, make sure that your Public Liability Insurance is fully compliant with EC 785/2004.
You also need a minimum amount of cover of 0.75 million special drawing rights (SDRs), which is about £0.75million.
Most insurance companies offer a least £1 million of public liability insurance as standard which more than covers you.