The Department of Health and Social Care has issued guidance for England, where new alert levels (medium, high and very high) have been introduced. At present, the guidance relating to funerals is the same for each alert level and confirms that attendance is limited to 30 for funerals and 15 for wakes and linked ceremonial events (for example, the scattering or burial of ashes). Scottish Government has issued an update on ‘Carrying The Cords And Coffin’ and the requirement for social distancing.
You can read the guidance for each alert level here:
https://www.gov.uk/guidance/local-covid-alert-level-medium
https://www.gov.uk/guidance/local-covid-alert-level-high
https://www.gov.uk/guidance/local-covid-alert-level-very–high