rent guarantor . com

Guarantor

I have a couple who are in a relatively new relationship. There are three children, two of whom have special needs. Mum is a stay at home mum/carer. Step-dad is a plumber. He went bankrupt three years ago and has some health issues. They have paid to use a site called rent.guarantor.com to be the guarantors as Mum is on top up benefits and also still has a mortgage with her ex, which is about to be settled I am told. I wanted to use rental insurance as the four bed property they want to rent from me has a large mortgage! They state that the rent.guarantee insurance is for the entire term of the tenancy. My questions are: is this the case? I can only see that it lasts for 12 months, after which they have to pay a very large sum to renew their policy, and this is only for a new tenancy. What happens if they don't take out more insurance? Also, the insurance only insures each against half of the rent. So if they break up, I am wondering how the rent is covered. She certainly could not cover the rent alone and it is far in excess of the local housing allowance. I would not be able to get RIG on this property as they will not pass my insurers credit checks. I really want to help them as they are about to become homeless, as their landlord is selling up. But I have to consider my situation as well! Does anyone have any experience of this situation and the rent insurance they have bought? (which is due to expire in a few days!)