Why it matters
What Sub-letting means for a landlord
Unauthorised subletting is rarely just a contractual annoyance. If extra occupiers take the property to three or more people from two or more households sharing facilities, it becomes an HMO, potentially a licensable one, and the licensing offence is **yours**, not the tenant’s, with a civil penalty of up to £40,000 and Rent Repayment Order exposure attached to it. Short-let subletting through platforms adds an insurance problem, since most landlord policies exclude it, and often a breach of the head lease in a flat. Deal with it as a breach of term under Ground 12, and check the property rather than relying on the tenancy agreement to have prevented it.
Worked example
How it plays out
Neil notices new faces at his flat in Bristol and finds short-let reviews online: his tenant has been letting the second bedroom through a booking site. Neil writes to the tenant pointing to the no-subletting clause and asks for it to stop, and checks his insurance and the head lease. When it continues, he serves notice on Ground 12, with screenshots of the listings as evidence.
Common mistakes
Where landlords go wrong
- 01Ignoring signs of subletting until an insurer or freeholder raises it.
- 02Forgetting that extra occupiers can make the property a licensable HMO.
- 03Raising it with the tenant before gathering any evidence.
What to do
A short checklist
- Include a clear subletting clause in the tenancy.
- Inspect with proper notice if you suspect subletting.
- Keep dated evidence of listings or extra occupiers.
Sources
Checked against these sources on 16 September 2026. A guide to the rules in England, not legal advice: for a dispute or a possession claim, speak to a solicitor.
