It is advisable u have business insurance.
To cover What Liability ?
If you don't have business insurance added to your insurance policy, then you are technically driving without valid insurance
i used to do delivery driving for a local indian takeaway, until i was stopped by the police and almost had my car siezed for no insurance due to this exact reason.
i had the normal sdp+commute insurance, but not the business use addon
it costs a bit more, but you dont have to add loads of business miles on to the policy, just a low amount will do to make sure you are
you don't need any form of liability insurance, just make sure the car is insured fully and you will be fine