If you don't have a mortgage on the property, you will not technically be obligated by law to have any kind of landlord insurance, although it is extremely unusual for a landlord to operate without any kind of insurance cover.
The majority of landlords will consider insurance as an important necessity, as without it they will be left exposed to a large number of potential hazards and dangers which could cause them a great deal of unnecessary financial expenditure.
If for example a landlord were to forgo the use of landlord liability insurance, they could be held responsible for paying substantial legal fees.
As a landlord, the owner must bear a certain degree of responsibility for the tenants who reside within their property. If this responsibility is ignored and a tenant were to become injured due to poorly maintained conditions within the property, a compensation claim against the landlord could be a very real possibility.
In order to address this problem, landlord liability insurance, something that is often included as standard in many insurance packages, will usually help in terms of financing any legal aid or expenses that may be incurred.
There are insurance providers which can advise you, and getting a few different quotes can help you to find the best deal.