If you share a house or flat with people who aren't part of your household — a classic "house share" — there's a good chance your property is legally an HMO (House in Multiple Occupation). Landlords who let HMOs without the licence the law requires are committing a criminal offence, and that offence is one of the most common grounds for a Rent Repayment Order (RRO) in London.
What Counts as an HMO?
A property is a mandatory-licensable HMO nationally if it's occupied by five or more people forming two or more separate households, and they share a kitchen, bathroom, or toilet. That's a large slice of shared housing in London — a five-bedroom house let room-by-room to five sharers almost always qualifies.
Many boroughs go further with additional licensing schemes, which lower that threshold. In Hackney and Islington, for example, a licence can be required for a property with just three occupants from two households. We cover the additional licensing angle separately in our guide to RRO and additional HMO licensing.
Why an Unlicensed HMO Is Grounds for an RRO
Operating a licensable HMO without a valid licence is a criminal offence under the Housing Act 2004. Because it's a qualifying offence under the Housing and Planning Act 2016, any tenant who paid rent during the unlicensed period can apply to the First-tier Tribunal for an RRO — regardless of whether the council has taken any action against the landlord.
You don't need the council to have prosecuted your landlord, and you don't need a criminal conviction. The Tribunal decides on the balance of probabilities, using its own civil process.
How to Check If Your HMO Should Be Licensed
- Count how many unrelated people live in the property and whether you share facilities.
- Check your borough's public HMO licence register — most London councils publish one online.
- If your address doesn't appear on the register but meets the threshold, the property is very likely unlicensed.
- An application that was submitted but not yet granted does not count as a valid licence — the offence is renting without a licence in force.
We check licensing registers for every borough we cover — Islington, Hackney, Newham, Haringey, Waltham Forest, Southwark, Lambeth, Brent, Lewisham and Tower Hamlets — as part of a free assessment, so you don't need to work this out alone.
How Much Could You Claim?
As with any RRO, the Tribunal can award up to 12 months of the rent you actually paid during the unlicensed period, and there's no need to show you suffered any financial loss beyond the rent itself. Our full guide to how RRO amounts are decided explains the factors the Tribunal weighs — including the landlord's conduct and any previous convictions.