Houses in multiple occupation
Shared houses and flats are defined and counted in several different ways in England. Each count answers a different question, and none of them is the number of HMOs.
7 definitions, drawn in different places
Housing law, planning, licensing, Section 257, council tax and the Census each draw the line in a different place. A property can be an HMO under one and not under another.
HMO under the Housing Act 2004 (section 254)
A home shared by 3 or more people who form 2 or more households (a household is one person or a family) and who share a kitchen, bathroom or toilet. It can be a house, a flat or a converted building, and it must be their main home.
Counts: Buildings meeting the standard, self-contained flat or converted building tests, plus section 257 blocks and buildings declared HMOs.
Does not count: Buildings listed in Schedule 14 (for example council or housing association homes, owner plus up to 2 lodgers, some student halls, care homes).
Planning use: Class C4 (small HMO) and sui generis (large HMO)
For planning, a home lived in by 3 to 6 unrelated people who share basic amenities is Class C4. With more than 6 people it falls outside any use class ("sui generis") and always needs planning permission. In Portsmouth a citywide Article 4 Direction means changing a family house (C3) to C4 also needs permission.
Counts: Lawful planning use of a property, decided through planning applications and certificates of lawfulness.
Does not count: Whether a property is licensed or safe. Section 257 converted blocks are excluded from C4.
Mandatory HMO licence (national)
Any HMO with 5 or more people forming 2 or more households must have a council licence, anywhere in England. Since 1 October 2018 the number of storeys does not matter.
Counts: HMOs of the prescribed description: 5+ occupiers, 2+ households, meeting the standard, self-contained flat (not purpose-built in a block of 3+) or converted building test.
Does not count: Smaller HMOs (3 or 4 people), which need a licence only where a council runs additional licensing.
Housing Act 2004 s55(2)(a); Licensing of HMOs (Prescribed Description) (England) Order 2018, art. 4
Additional HMO licence (local scheme)
A council can require smaller HMOs to be licensed too, in all or part of its area, for up to 5 years. Portsmouth's citywide scheme runs from 1 September 2023 to 31 August 2028 and covers HMOs of 3 or more people in 2 or more households, plus mainly tenanted section 257 buildings.
Counts: HMOs in the designated area that are not already covered by mandatory licensing.
Does not count: Areas or HMO types outside the designation. Schemes differ by council, so additional-licence counts are not comparable between areas.
Housing Act 2004, s56; Portsmouth designation made 22 Nov 2022
Section 257 HMO (converted block of flats)
A building converted into self-contained flats where the conversion did not meet the 1991 Building Regulations and fewer than two-thirds of the flats are owner-occupied. The licence is for the building; individual flats may need their own HMO licence as well.
Counts: Whole converted buildings meeting the s257 test. In Portsmouth, only mainly or wholly tenanted s257 buildings are in the additional-licensing scheme.
Does not count: Purpose-built blocks or conversions that meet the 1991 standard.
Council tax: owner-liable HMO (Class C)
For council tax, the owner rather than the tenants pays on a dwelling built or adapted for people who are not one household, or where each tenant rents only part of it, or which is an HMO.
Counts: Who is liable for council tax on a dwelling.
Does not count: Planning status or licensing. Council-tax HMO flags are not published as an HMO count.
Council Tax (Liability for Owners) Regulations 1992, reg. 2, Class C
Census 2021 HMO dwelling (ONS RM192)
ONS counts a dwelling as an HMO when at least 3 unrelated people forming more than one household rent it from a private landlord and share a toilet, bathroom or kitchen. Small = 3 or 4 unrelated tenants; large = 5 or more.
Counts: Occupied dwellings on Census Day, 21 March 2021, classified from Census responses; the same rule applies to every area.
Does not count: Licensing or planning status; changes since March 2021. Small counts are perturbed for confidentiality.
Three national numbers, three different measures
Each sentence below carries its measure. None of them is a count of all HMOs in England today.
Different methods.The Census applies one rule to every home on one day in 2021. The council estimate is each council's own best guess, made its own way. The licence count covers mandatory licences only. Do not add these together, subtract one from another or read them as a trend.
- 458,855 HMOs estimated by English councils at March 2025.
- 175,661 dwellings identified as HMOs in Census 2021.
- 95,217 mandatory HMO licences reported in LAHS at March 2025.
458,855
Sum of council estimates of all HMOs (LAHS f8a), 295 of 296 English councils
Not the same as: a count of all HMOs in England. Each council uses its own estimation method.
Local Authority Housing Statistics open data 1978-79 to 2024-25 (items f8a, f9a, f10a)
175,661
Census 2021 HMO dwellings (small + large), sum of 309 English LAs
Not the same as: a current total. 0.705% of all dwellings; a fixed 2021 benchmark.
Census 2021 RM192: number of dwellings that are HMOs (edition 2021, version 2)
95,217
Dwellings with a mandatory HMO licence (LAHS f10a), 289 of 296 English councils
Not the same as: all HMO licences. Excludes additional and selective licences; 7 councils did not report a figure.
Local Authority Housing Statistics open data 1978-79 to 2024-25 (items f8a, f9a, f10a)
Coverage of the council figures. There is no England row in the LAHS open data, so the England figures are sums of the councils that reported: 295 of 296 councils for the estimate of all HMOs, 283 of 296 for the estimate of mandatory-licensable HMOs, and 289 of 296 for mandatory licences. Councils that did not report a figure are left out, not counted as zero. Not published for mandatory licences: Croydon, East Cambridgeshire, Lincoln, Preston, Telford and Wrekin, Tewkesbury, West Berkshire.
Oxford is first of 309 English councils on the Census measure
Census 2021 is the only national source that applies one definition everywhere. On it, 0.705% of dwellings in England were HMOs. Oxford was highest at 4.517%; Southampton ranked 20th and Portsmouth 26th of 309.
HMO dwellings as a share of all dwellings, by region, Census 2021
Regions are sums of their council rows (London 33, South West 30, South East 64, East Midlands 35, Yorkshire and The Humber 21, North East 12, North West 39, West Midlands 30, East of England 45). ONS adjusts small cells for confidentiality, so sums can differ slightly from other ONS tables.
The 30 councils with the highest share
| Rank | Council | Region | HMO dwellings | Share |
|---|---|---|---|---|
| 1 | Oxford | South East | 2,664 | 4.517% |
| 2 | Wandsworth | London | 6,456 | 4.291% |
| 3 | Lambeth | London | 5,919 | 4.043% |
| 4 | Cambridge | East of England | 2,243 | 3.976% |
| 5 | Exeter | South West | 2,000 | 3.595% |
| 6 | Hackney | London | 4,159 | 3.575% |
| 7 | Tower Hamlets | London | 4,734 | 3.520% |
| 8 | Bristol | South West | 6,904 | 3.404% |
| 9 | Hammersmith and Fulham | London | 2,926 | 3.150% |
| 10 | Islington | London | 3,346 | 3.130% |
| 11 | Nottingham | East Midlands | 4,151 | 3.088% |
| 12 | Southwark | London | 4,259 | 3.000% |
| 13 | Norwich | East of England | 2,026 | 2.996% |
| 14 | Brighton and Hove | South East | 3,843 | 2.937% |
| 15 | Newcastle upon Tyne | North East | 3,677 | 2.838% |
| 16 | Lincoln | East Midlands | 1,197 | 2.653% |
| 17 | Bath and North East Somerset | South West | 2,075 | 2.467% |
| 18 | Manchester | North West | 5,528 | 2.373% |
| 19 | Canterbury | South East | 1,596 | 2.349% |
| 20 | Southampton | South East | 2,539 | 2.349% |
| 21 | Camden | London | 2,515 | 2.324% |
| 22 | Haringey | London | 2,611 | 2.304% |
| 23 | Guildford | South East | 1,353 | 2.292% |
| 24 | Reading | South East | 1,633 | 2.265% |
| 25 | York | Yorkshire and The Humber | 2,048 | 2.259% |
| 26 | Portsmouth | South East | 1,933 | 2.120% |
| 27 | Newham | London | 2,346 | 1.877% |
| 28 | Runnymede | South East | 694 | 1.872% |
| 29 | Westminster | London | 2,225 | 1.726% |
| 30 | Lewisham | London | 2,194 | 1.669% |
All 309 councils, and the council estimates for each, in the data tables →
Census Day was 21 March 2021. This is a fixed benchmark, not a current count, and it says nothing about licensing or planning status. A map is not shown; every value is in the tables.
Mandatory licensing is national; additional licensing is local
Councils estimated 132,246 HMOs needed a mandatory licence at March 2025 (283 of 296 councils) and reported 95,217 mandatory licences (289 of 296).
Mandatory HMO licence (national)
Any HMO with 5 or more people forming 2 or more households must have a council licence, anywhere in England. Since 1 October 2018 the number of storeys does not matter.
Additional HMO licence (local scheme)
A council can require smaller HMOs to be licensed too, in all or part of its area, for up to 5 years. Portsmouth's citywide scheme runs from 1 September 2023 to 31 August 2028 and covers HMOs of 3 or more people in 2 or more households, plus mainly tenanted section 257 buildings.
LAHS reports mandatory licences only. Additional-licence counts are not collected nationally, and each scheme covers a different area and set of HMOs, so they cannot be ranked between councils. UK Stat Pack does not yet hold a national list of local schemes; Portsmouth's citywide scheme is set out in the Portsmouth case study.
Safety, management, space and amenities
Shared homes carry more fire and management risk than a single household, because more unrelated people depend on the same exits, kitchens and bathrooms.
- Management. A licence tests whether the licence holder and manager are fit and proper and whether management arrangements are adequate.
- Space and amenities. Licences set the maximum number of occupiers and require enough kitchens, bathrooms and toilets for them.
- Safety. Licence conditions cover gas, electrical and fire safety. Any rented home can also be assessed under the Housing Health and Safety Rating System.
- Enforcement. Running a licensable HMO without a licence is an offence, and tenants may be able to seek a rent repayment order.
Legal basis: Housing Act 2004 Part 2 and the 2018 Prescribed Description Order.
Lower-cost rooms for people living alone or sharing
Census 2021 identified 130,733 small HMOs (3 or 4 unrelated tenants) and 44,928 large HMOs (5 or more) in England.
HMOs house students, workers, contractors and people on lower incomes who cannot afford, or do not need, a self-contained home. Councils also use HMO rooms to prevent and relieve homelessness. There is no national series on that housing role; Portsmouth's council has published one year of local figures, shown in the case study. The people who live in HMOs are residents, not the problem: the policy questions are concentration, standards and what replaces lost rooms.
Licences, standards, complaints and enforcement
The national returns stop at mandatory licensing. The things residents most want to know are not published as a national series.
- All licences. Dwellings with a mandatory HMO licence issued at 31 March. Additional and selective licences are not included, so there is no national total of HMO licences.
- Standards. Mandatory-licensable HMOs found with Category 1 hazards: 2,105 at March 2025, from 273 of 296 councils. It covers mandatory-licensable HMOs only.
- Complaints. Not published as a national series.
- Enforcement. The LAHS items used here (f8a to f11a) do not cover notices, penalties or prosecutions.
Which numbers can be compared, and how
These rules are held in the data registry and applied to every chart on these pages: measures from different groups are never joined in one line.
| Measure | Between areas | Over time |
|---|---|---|
| ONS Census RM192 rate | Comparable. Same definition and date for every area in the same Census edition. | Fixed 2021 benchmark only; no trend until a new Census edition. |
| LAHS total HMO estimate (f8a) and mandatory-licensable estimate (f9a) | Qualified. Each council chooses its own estimation method. | Show with a local-method warning and the published revisions; never call it a measured rise. |
| LAHS mandatory licences (f10a) | Comparable. National statutory category, subject to reporting quality; some LAs report [x]. | Valid annual series; mark the October 2018 widening of mandatory licensing. |
| Portsmouth combined register | Local only. Local operational measure. | Only across retained snapshots, with category, September 2023 and June 2026 system-change notes. |
| Portsmouth vs Southampton live registers | Not comparable. Different scheme geography (Portsmouth citywide; Southampton selected wards), categories and application status. | Do not rank. |
| Complaint rates (2019 SPD) | Local only. Local and dated. | Do not extend beyond the source period. |
| Planning records (AMR) | Local only. Local policy and process measure. | Track only after category reconciliation (2023/24 counted determined, 2024/25 counted received). |
| Planning HMO map (licensed + possible/unknown) | Local only. Planning-monitoring estimate; method unpublished. | Two dated points only (Jan 2025, Dec 2025); do not join with register or LAHS. |
| Housing role (homelessness placements) | Local only. Single-year figures from a council report. | No series published. |
Common claims, checked against the measures
“England has 458,855 HMOs”
MisleadingWhat is known: 458,855 HMOs estimated by English councils at March 2025. It is a sum of 295 councils' own estimates, each made with its own method.
What is not known: How many HMOs there are in England today. No source counts them all on one definition.
“Portsmouth gained 2,080 HMOs between 2018/19 and 2023/24”
MisleadingWhat is known: Portsmouth's council estimate was 3,920 in 2018/19 and 6,000 in 2023/24. In between: 4,440 (2019/20), 6,828 (2020/21), 6,000 (2021/22), 6,000 (2022/23). These are estimates made with a local method, not measured counts.
What is not known: How many properties physically changed use.
“Additional licensing caused more HMO conversions”
UnverifiableWhat is known: Portsmouth's citywide scheme started on 1 September 2023, which brought smaller HMOs onto the register for the first time. Licence counts before and after are not a stock trend: coverage expanded.
What would change this verdict: Planning-use data on conversions, reconciled with licensing records, over the same period.
“Portsmouth has the highest HMO share in Hampshire”
IncorrectWhat is known: On Census 2021, Southampton's share was 2.349% and Portsmouth's 2.120%.
“Portsmouth's HMO share is well above England's”
SupportedWhat is known: Census 2021: 2.120% of Portsmouth dwellings against 0.705% for England, about 3.0 times the England rate.
Portsmouth: high, concentrated and hard to count with one number
- Census 2021: 2.120% of dwellings were HMOs, about 3.0 times England and about 8.5 times the Hampshire County Council area.
- The council register held 3,107 records in licensed categories in September 2026.
- 69.7% of combined-register records were in three wards.
▸How these figures are produced
HMO dwellings = small + large; all dwellings = small + large + does-not-apply; share = HMO / all. England and Hampshire CC area are sums of 2021 LA rows.
ONS RM192 edition 2021 version 2, released 28 April 2023; checked 23 September 2026. LAHS open data items f8a to f11a for 2024/25; checked 23 September 2026.
Full sources, freshness states and validation rules: HMO methodology.
Data version: Portsmouth register c56e8282b357 · ONS RM192 e3e5b7fcb885 · LAHS 6b5f0105d344 (first 12 characters of each source file's SHA-256).