Houses in multiple occupation (HMOs), also known as houses of multiple occupancy, is a term which refers to residential properties where ‘common areas’ exist and are shared by more than one household. Common areas may be as significant as bathrooms and kitchens / kitchenettes, but may also be just stairwells or landings. HMOs may be divided up into self-contained flats, bed-sitting rooms or simple lodgings.

Strictly speaking, HMOs are not the same as purpose-built flat blocks, since most will have come into being as large buildings in single household occupation.

HMO licensing was first introduced in Scotland in 2000. To be granted a licence under the scheme, properties must meet certain standards, such as presence of smoke detectors and fire doors. These provisions were included in response to a fatal fire at a student flat in Glasgow, which had no working smoke detectors, and metal bars preventing escape through a window.

HMO schemes have been subsequently introduced to other parts of the UK, though the definition of what constitutes an HMO varies between Scotland, Northern Ireland, and England & Wales. Local authorities, who manage and enforce the licensing of HMOs, have the power to vary the conditions of the licence. Failure to apply for or comply with the terms of a licence for an HMO constitutes a criminal offence.

Smaller HMOs in England & Wales, comprising for example a terraced house shared by young transient professionals, require mandatory licensing under the Housing Act 2004 if the property comprises five tenants and three floors (sometimes two floors).

HMOs have now become  Mandatory, so you will have to get licensed.