Skip to main content

Information on houses in multiple occupation (HMOs) and HMO licensing as at 31 March 2023.


This information has previously been included in the ‘Housing hazards and licenses’ report. Please see previous publications of Housing hazards and licenses for earlier years.


HMO licensing was introduced under the Housing Act 2004 to help ensure that HMOs are well managed. Local authorities are responsible for the mandatory licensing of larger, higher risk HMOs (with a minimum of three stories and five occupants). Local authorities also have the discretion to extend licensing to other categories of HMOs to address particular problems that may exist in smaller properties or in particular geographical areas.

Main points

Between 31 March 2017 and 31 March 2021, the number of mandatory licenses decreased from 2,973 to 2,443. In the most recent two years, the number of mandatory licenses has increased, with 2,619 mandatory licenses recorded at 31 March 2023.

Since 31 March 2018, the number of additional licenses has steadily declined, from 6,056 in 2018 to 4,332 in 2023. This decrease is largely owing to a pause in the additional licensing of the Cathays community ward of Cardiff (this licensing was recently reintroduced in 2023).

Figure 1: Percentage of all assessments found to contain at least one Category 1 or Category 2 hazard, 2013-14 to 2022-23 [Note 1]


Description of Figure 1: Line graph showing that the number of mandatory and additional licenses peaked at 31 March 2018.

Source: Hazards and Licenses returns from local authorities

[Note 1] Data not collected for March 2020 due to the impact of the COVID-19 pandemic.

At 31 March 2023, the local authorities with the highest number of licensed HMOs were Cardiff (2,187) and Swansea (1,693), both large urban areas with high levels of private rented dwellings and student populations.

Figure 2: Number of estimated and known HMOs, 31 March 2014 to 31 March 2023


Description of Figure 2: Clustered bar chart showing that in the past 10 years the number of estimated HMOs has fluctuated between 18,167 and 19,587 while the number of known HMOs has fluctuated between 14,070 and 15,247.

Source: Hazards and Licenses returns from local authorities

[Note 1] Data not collected for March 2020 due to the impact of the COVID-19 pandemic.

At 31 March 2023, local authorities estimated there were a total of 18,252 HMOs in Wales, a 5% decrease on the previous year. This was accompanied by a decrease in the number of HMOs known to local authorities (from 14,697 in March 2022 to 14,434 in March 2023). At 31 March 2023, 79% of estimated HMOs were known to local authorities.

Cardiff and Swansea reported the highest numbers of estimated HMOs in Wales (7,000 and 2,100 respectively). In Cardiff and Swansea, a high proportion of estimated HMOs were known to the local authority (92% in Cardiff and 89% in Swansea). In contrast, Denbighshire reported the third highest number of estimated HMOs (1,345) with a much smaller proportion of these HMOs known to the local authority (16%).


Datasets and interactive tools


Holly Flynn

Rydym yn croesawu gohebiaeth yn Gymraeg / We welcome correspondence in Welsh.


Telephone: 0300 025 8099

Rydym yn croesawu galwadau yn Gymraeg / We welcome calls in Welsh.