Does every HMO in Wales need a licence?

Not under mandatory licensing, which covers HMOs of 3 or more storeys with 5 or more people. Councils can require licences for others through additional licensing.

Do I need planning permission for an HMO in Wales?

Yes, for a change from a house to a C4 HMO (3–6 sharers) and for larger HMOs. Wales does not have England’s permitted development right from C3 to C4.

What is Rent Smart Wales?

The registration and licensing scheme for landlords and agents in Wales. Every landlord must register, and anyone carrying out letting or management work needs a licence.

What alarms are required in Wales?

Mains-powered, interlinked smoke alarms on every storey and CO alarms where there is a gas, oil or solid-fuel appliance, under the fitness for human habitation rules.

HMO Rules in Wales 2026 | HMO Refurbishment

In short: In Wales mandatory HMO licensing still applies only to HMOs of 3 or more storeys with 5 or more people, councils run additional licensing for others, every landlord must register with Rent Smart Wales, and changing a house to a C4 HMO always needs planning permission.

What counts as an HMO in Wales?

The Housing Act 2004 definitions apply in Wales as in England: broadly, 3 or more people who are not one household, sharing basic amenities, as their main home.

When is a licence needed?

Mandatory licensing: HMOs with 3 or more storeys, occupied by 5 or more people in 2 or more households. Wales did not adopt England’s 2018 removal of the storey test.
Additional licensing: councils can license other HMOs in designated areas. Swansea, for example, continued its scheme in Castle, Uplands, St Thomas and Waterfront wards from February 2026.
Rent Smart Wales: every landlord must register (valid 5 years), and those doing letting or management work need a licence, with approved training.

What room sizes apply?

England’s national minimum room sizes do not apply in Wales. Each council sets its own room and amenity standards.

Do I need planning permission?

Since February 2016 Wales has a C4 use class for 3–6 unrelated sharers, but the permitted development right only runs from C4 to C3. Changing a house to a C4 HMO needs planning permission.
More than 6 sharers is sui generis and needs permission. Cardiff, for example, applies HMO concentration thresholds of 20% in Cathays and Plasnewydd and 10% elsewhere within a 50 m radius.

What safety rules apply?

Under the Renting Homes (Wales) Act 2016 fitness rules (from 1 December 2022): mains-powered, interlinked smoke alarms on every storey; CO alarms where there is a gas, oil or solid-fuel appliance; and an electrical inspection and test at least every 5 years, with the report given within 14 days.
An annual gas safety check by a Gas Safe registered engineer.
Council HMO standards and the fire risk assessment set detection grades, fire doors and escape routes.

What energy standard applies?

At least EPC E for most lets. Whether the planned EPC C by 2030 policy will apply in Wales has not been confirmed.

Sources

Checked 31 October 2026. General information for landlords planning works, not legal advice.

HMO rules in Wales