Here is some information on households and social distancing. A reminder that a HMO household is classed as one household; https://www.gov.uk/government/publications/coronavirus-covid-19-meeting-with-others-safely-social-distancing/coronavirus-covid-19-meeting-with-others-safely-social-distancing
Information on support bubbles and who is allowed to form a support bubble; https://www.gov.uk/guidance/making-a-support-bubble-with-another-household#what-a-support-bubble-is
Information on childcare bubbles; https://www.gov.uk/guidance/making-a-childcare-bubble-with-another-household
And information on Christmas bubbles; https://www.gov.uk/government/publications/making-a-christmas-bubble-with-friends-and-family/making-a-christmas-bubble-with-friends-and-family
Landlords should familiarise themselves with the rules on bubbles, especially HMO landlords who may receive queries from tenants.
