Do You Need an HMO Licence for Airbnb or Short-Lets in London?

We're asked a version of this question regularly, and the honest answer is that HMO licensing and short-let rules are two separate legal regimes that landlords often conflate. Understanding the difference matters, because getting it wrong can mean falling foul of one set of rules while thinking you have covered the other entirely.

HMO licensing is about who lives there, not how long

HMO licensing is triggered by the number of unrelated households sharing a property on a long-term residential basis — broadly, three or more people from two or more households sharing amenities brings a property within scope for additional licensing where a borough has a designated scheme, with mandatory licensing kicking in at five or more people from two or more households regardless of borough scheme. A short Airbnb-style booking to a single group — a family, or a group of friends travelling together, counted as one household for the duration of the stay — does not on its own create an HMO, because it is not multiple separate households sharing under one roof. The legal test looks at household composition, not the length of the letting arrangement.

The 90-day rule is the actual short-let control

The regulation that specifically governs short-lets in London is the 90-day rule under Section 44 of the Deregulation Act 2015. A residential property in Greater London cannot be let out on a short-term basis for more than 90 nights in a calendar year without planning permission for a change of use. This is entirely separate from HMO licensing: it is enforced through planning law rather than housing licensing law, the relevant authority is the planning department rather than the housing licensing team, and the consequence of breaching it is an unauthorised change of use, not an unlicensed HMO offence.

Why landlords conflate the two regimes

The confusion is understandable because both regimes are about how a property is occupied and both sit with the local council, but they answer different questions. HMO licensing asks: how many unrelated households share this property, and does that number cross a threshold requiring a licence for how the building is configured and managed. The 90-day rule asks: how many nights per year is this specific property being used for short-term letting, regardless of who occupies it or how many households are involved. A landlord can be entirely compliant on one front and in clear breach of the other, and neither regime's paperwork will alert them to a problem with the other.

Where the two can genuinely overlap

The situations that need real care are mixed-use ones: a property operating as a licensed HMO with individual rooms let to separate long-term sharers, where one or more rooms are also advertised short-term to different guests through a platform. That arrangement raises HMO licensing questions — do the short-term occupants count as a separate, additional household, changing the total household count on which the existing licence was based — and short-let planning questions simultaneously, since is the property, taken as a whole, now effectively conducting short-term letting activity subject to the 90-day cap on top of its licensed HMO status. Councils that encounter this combination during an inspection tend to scrutinise it closely, precisely because it sits across two enforcement teams.

What happens if you get it wrong

Breaching the 90-day rule without planning permission is a planning enforcement matter, which can result in an enforcement notice and, if ignored, prosecution for continued unauthorised use — separate from, and in addition to, any HMO licensing penalty. Operating an unlicensed HMO where one is required carries its own separate civil penalty regime, now tiered up to £7,000 for minor or initial non-compliance and up to £40,000 for serious or repeat non-compliance under the Renters' Rights Act 2025, plus potential Rent Repayment Order claims from any long-term sharers in the property. Because the two regimes are enforced by different teams, a landlord can receive action on both fronts from the same council over what looks, from the landlord's perspective, like a single letting arrangement.

Practical steps before you list a property

Before listing a property on Airbnb or a similar platform, work out honestly which category the arrangement actually falls into: purely short-term to single groups (90-day rule applies, HMO licensing generally does not), a genuine long-term HMO with separate household sharers (HMO licensing applies, 90-day rule generally does not), or some blend of both (both regimes potentially apply, and need separate checking). Keep a straightforward record of nights let short-term across the calendar year if you are relying on staying under the 90-day threshold, since that is the figure a planning enforcement inquiry will ask for first.

Get clarity before you list, not after an inspection

If you are planning to let a property on Airbnb or a similar platform in London, or you are already doing so alongside a longer-term HMO arrangement, it is worth getting clarity on both regimes before a council inspection raises the question rather than after. Contact us and we will help you understand exactly where your property sits, and whether an additional or mandatory HMO licence is needed for any long-term sharing element of the arrangement.