HMO Licensing in Cardiff

Cardiff is a great student HMO market, but in 2026 you are dealing with three layers: Cardiff HMO licensing, Rent Smart Wales registration/licensing, and Article 4 plus density caps in the core student wards.

How Welsh HMO licensing works (Cardiff, 2026)

Mandatory HMO licensing (Housing Act 2004, Wales)

As in England, a mandatory HMO licence is needed where:

• The property has 5 or more occupiers,
• In 2 or more households,
• Sharing kitchen/bathroom/WC.

Mandatory licensing applies across the whole of Cardiff.

Additional licensing (Cathays and Plasnewydd)

Cardiff runs additional HMO licensing schemes in:

• Cathays
• Plasnewydd (covers much of Roath).

Cathays: Additional licensing scheme first started 1 July 2010, renewed 1 January 2016, and has been re-designated from 1 February 2023 for 5 years.

Applies to all HMOs in Cathays (subject to statutory exemptions), not just 5+ occupiers.

Plasnewydd: Additional scheme first started 3 November 2014, renewed 1 January 2021 for 5 years, so current Plasnewydd additional scheme runs to 31 December 2025.

CPS Homes confirms the scheme ends 31 December 2025, with no formal decision yet on re-declaration, though a further scheme is expected after consultation.

Effect in 2026:

• Cathays: firmly under additional licensing to at least 31 Jan 2028.
• Plasnewydd/Roath: additional licensing runs to 31 Dec 2025, then either lapses or is re-declared (expect consultation and likely renewal).

Under these schemes: many smaller HMOs with 3+ unrelated occupiers in Cathays/Plasnewydd require a licence, not just 5+ sharers.

Rent Smart Wales: the extra Welsh layer

This is the big difference vs England.

Rent Smart Wales is the national registration and licensing authority for all landlords and agents letting property in Wales.

If you own and let property in Cardiff:

• You must be registered with Rent Smart Wales as a landlord.
• If you self-manage, you must also hold a landlord licence via Rent Smart Wales, including approved training.
• If you use a letting agent, the agent must hold their own Rent Smart Wales licence.

Rent Smart Wales compliance is an explicit condition of Cardiff HMO licences: Cardiff will not grant / renew an HMO licence if the landlord / agent is not correctly registered/licensed with RSW.

So compared to England: in Cardiff you must satisfy both:

1. Rent Smart Wales (national registration/licensing), and
2. Cardiff's HMO licence (mandatory/additional) for each property.

Article 4 and density caps

Article 4 Directions

Cardiff uses Article 4 Directions to control the spread of HMOs. Official planning guidance confirms:

Article 4 applies across large parts of Cathays and Plasnewydd (Roath), with an HMO Supplementary Planning Guidance (SPG) that introduces HMO concentration thresholds.

HMO concentration thresholds

Cardiff's HMO SPG sets two tests:

In Cathays and Plasnewydd: If more than 20% of dwellings within a 50m radius of the proposed HMO are already HMOs (C4 or sui generis), the new HMO is considered unacceptable in planning terms.

In all other wards: The threshold is 10% within 50m.

This is why local groups say Cardiff has "effectively stopped new HMOs" in Cathays: many streets are already above 20%.

Effect: Any new C3 to C4 HMO in these areas needs planning permission and must pass the 20%/10% density test on top of licensing.

Fees and standards

Licence fees (Cardiff HMO)

Shared Regulatory Services (SRS) fee table for Cardiff HMOs shows two-part fees (application + grant) varying by size:

• HMO shared house / single flat up to 4 bedrooms:

• Application: GBP 230

• Grant: GBP 650

• Total: GBP 880.

• 5-9 bedrooms:

• Application: GBP 250

• Grant: GBP 700

• Total: GBP 950.

• 10-15 bedrooms:

• Application: GBP 440

• Grant: GBP 750

• Total: GBP 1,190.

The final fee depends on compliance: non-compliant properties can face higher effective costs via shorter licence terms, extra inspections, etc.

Room size standards

Cardiff adopts the standard UK HMO minimums:

• Under-10: 4.64 sq m minimum.
• One person over 10: 6.51 sq m.
• Two people over 10: 10.22 sq m.

These are enforced via licence conditions and inspections.

Student HMO market and key areas

Universities

Cardiff University, Cardiff Metropolitan University, and University of South Wales (Cardiff campus) drive a large student HMO market in CF24/CF10.

Core HMO areas

Cathays (CF24): Primary student area; high HMO density, Article 4, additional licensing, and 20% cap.

Roath / Plasnewydd (CF24): Mix of students and young professionals; additional licensing (to 31 Dec 2025) and Article 4 with 20% cap.

Adamsdown / Splott: Growing HMO share; 10% cap applies; some student spill-over plus working tenants.

Typical room rents

Typical PBSA prices show the ceiling; HMOs sit below this:

• PBSA in Roath/City Road advertised at GBP 215-231 per week bills included.

Student house rooms in Cathays/Roath via Cardiff Student Letting show:

• Rooms around GBP 160 per week in sharer houses, bills often extra.

For HMOs, a realistic assumption:

• Standard student room in Cathays/Roath: GBP 120-160 per week (roughly GBP 520-700/month), depending on whether bills are included.

Enforcement approach

HMO licensing in Cardiff is administered by Shared Regulatory Services, with clear guidance and inspection-led enforcement.

Enforcement tools include:

• Refusal or revocation of licences.
• Shorter licence terms for poor management.
• Prosecutions and civil penalties for unlicensed HMOs.
• Rent Smart Wales can separately fine or prosecute landlords who fail to register or get the correct landlord licence.

Cardiff's HMO SPG and data show how concentrated HMOs are in Cathays and Plasnewydd (86% of mandatory HMOs city-wide were in these two wards as of 2016). That has driven:

• Article 4 + density caps.
• Expansive additional licensing.
• Active monitoring of HMO development and licensing compliance.

Compared to many English cities, Cardiff adds Rent Smart Wales and Welsh housing law (occupation contracts, FFHH standards) into the mix, increasing the compliance load.

How Welsh law changes the picture vs England

Key differences for you as an HMO landlord:

Rent Smart Wales: You must register as a landlord and either hold a landlord licence (if self-managing) or use a licensed agent. This is separate from and on top of HMO licensing.

Occupation contracts vs ASTs: Welsh law has replaced Assured Shorthold Tenancies with standard occupation contracts under the Renting Homes (Wales) Act, changing notice periods and contract terms.

FFHH (Fitness for Human Habitation): Stronger statutory standards which the council and Rent Smart Wales both enforce.

In short: running an HMO in Cardiff is closer to running a regulated housing service than a simple BTL.

What forums get wrong about Cardiff HMOs

Myth 1: "Only 5+ sharer HMOs need licences; my 4-bed in Cathays is fine."

Reality: Mandatory licensing hits 5+ HMOs city-wide, but additional licensing in Cathays and Plasnewydd means many 3-4-sharer HMOs there also need licences.

Myth 2: "The Plasnewydd scheme ended, so Roath is free now."

Reality: The current Plasnewydd additional scheme runs to 31 December 2025. There is no re-declaration yet, but local agents expect a new scheme after consultation. Treat any gap as temporary, not a free-for-all.

Myth 3: "Article 4 just means I need to fill in an extra form."

Reality: Article 4 + the HMO SPG mean new HMOs fail if >20% of dwellings within 50m are HMOs in Cathays/Plasnewydd, or >10% elsewhere. In saturated Cathays streets you are effectively blocked from creating new HMOs.

Myth 4: "Cardiff is like an English city plus a bit of extra admin."

Reality: Welsh law adds:

• Rent Smart Wales registration/licensing.
• Occupation contracts, not ASTs.
• Stronger FFHH and enforcement integration between RSW and the council.

Run Cardiff HMOs like a serious, regulated business or do not run them at all.

How to present Cardiff on PropertyKiln

Licensing stack: Mandatory HMO for 5+ sharers city-wide, GBP 880-950+ depending on size. Additional HMO licensing in Cathays (to 2028) and Plasnewydd/Roath (to end 2025). Rent Smart Wales registration/licensing mandatory for all landlords and agents.

Planning: Article 4 across Cathays/Plasnewydd with 20%/10% HMO density caps within 50m.

Market: Strong student demand in Cathays, Roath, Adamsdown/Splott with rooms typically GBP 120-160/week, solid yields if you price in full compliance costs.

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