The prescribed mandatory description includes three or more storeys and five or more people in two or more households, subject to the full statutory tests. Basements and other storeys need careful counting. Additional schemes and converted-flat rules need a separate council check.
Establish the actual household arrangement
Start with who lives in the building, how they are related, which facilities they share and whether it is their main home. Count occupation across the relevant building arrangement.
- The usual mandatory Welsh licensing test includes three or more storeys, five or more occupants and two or more households, subject to the full statutory definition and exceptions.
- Ask the council whether additional licensing applies below the mandatory threshold. The absence of three storeys does not settle every Welsh HMO licensing question.
- Check converted buildings and self-contained flats carefully. The legal HMO definition and a particular licensing designation are separate questions.
Check the accommodation and conditions
Do this before agreeing a new occupier or converting another room into a bedroom.
- Compare the licence and local standards with room sizes, kitchen and washing facilities, fire precautions and maximum permitted occupation.
- Keep the licence holder and manager details current. Rent Smart Wales registration and licensing remain separate checks.
- Confirm planning permission, any material change of use and building control for conversions or alterations. An HMO licence does not retrospectively approve building work.
Manage a shared home as a whole
Individual room agreements can obscure responsibilities for shared areas. Set out who inspects, cleans, reports and repairs them.
- Record escape-route checks, damage to fire doors, blocked passages and faults with shared facilities. Give occupants a clear reporting route.
- Review visitors becoming residents and changes in household relationships before occupation limits are exceeded.
- Keep council correspondence, licence conditions and work completion evidence together. Seek written clarification where a condition conflicts with the proposed layout.
Example: adding a fourth letting room
A fictional landlord proposes using a former living room as another bedroom. Before advertising, check the resulting occupancy, amenities, licence conditions, planning position and fire strategy. A room having a window does not establish that it can lawfully be let.
What to do
- Record residents, households, storeys, shared facilities and conversion history.
- Check the current council scheme and occupancy standards.
- File HMO permission separately from Rent Smart Wales and planning records.
Evidence to keep
- Floor plans and occupancy schedule
- Council licensing decision and conditions
Sources and guidance
- HMO mandatory licensing: prescribed descriptions, article 3legislation.gov.uk · checked 20 October 2026