We had a DAS Rent and Legal policy organised through Letrisks in Southampton.
I think the excess was one month's rent, and when the tenant defaulted DAS settled the claim reasonably quickly, and organised and paid for the eviction.
I use L and G. But you must tell them when tenant changes, when property is empty and you must have an ASHT in place, its no good if left to go to rolling tenancy after 12 month ASHT is up.