The Housing Act 2004 brought licensing in for certain categories of HMO. If the definition determines a property within Harrow Council to be a HMO, it is almost certain that the landlord or their agent will need a licence. There are two ways in which licensing may apply to a HMO:

Additional and Mandatory Licensing (required by law)

Currently, HMOs of three or more storeys and with five or more occupants must be licensed under the government's mandatory licensing scheme.

From 24 August 2010 the London Borough of Harrow has been included in an Additional Licensing Scheme which will run concurrently with the mandatory licensing scheme.

This means that subject to specific exclusions contained in the designation, all properties occupied by three or more people in two or more households are licensable HMOs regardless of the number of storeys.