Caravan site fees

My client has recently moved to a caravan which his uncle has bought for him. It is on a fixed site and the client is responsible for paying site fees which amount to about £4,800/year. He claims UC and I understand that he can get help with site fees (site rent) through UC. Does anyone know the level of help he can get through UC? Is it for example based on the LHA or is it separately determined by an LA rent officer?

It’s just LHA.

Elliot - great, many thanks for your response