Understanding changes to the rules on housing multiple occupants is confusing. The rules change often, and there are different criteria for certain situations. But is this confusion costing you money and time.  To become a HMO specific criteria are required. At least 3 tenants live at the property and you share a kitchen, bathroom and toilet. This would be considered a small HMO. A large HMO would consist of 5 tenants forming more than one household in which a kitchen, bathroom and toilet are shared.