Property insurance (building + contents)
Specialist 'serviced accommodation' or 'holiday let' policy. Schofields, Pikl, and several other specialists offer these. £400-£700/year typically for a 4-bed.
Public liability (£5m minimum)
Included in most specialist policies. Required by corporate clients and most partner platforms (TNS requires £5m minimum to list).
Loss of income / cancellation
Optional but worth considering for high-value properties where a 2-month repair would be financially painful. Usually £100-£200/year additional.