New data shows that 2,712 properties under Westminster City Council are currently being investigated for unlawful short-term letting (as of the 30th March 2026).
The Property Buying Company sent Freedom of Information requests to local authorities in London to find out the number of recorded properties in breach of the 90-night rule.
In London, you can legally rent your property as a short-term let for a maximum of 90 nights within a calendar year. To exceed this limit, landlords would need to request planning permission from their local council to seek approval.
The law was introduced to protect homes for Londoners and reduce issues caused as a result of short-term lets, such as noise disturbance and rubbish left outside properties.
In 2025, Westminster City Council opened 499 new short-term letting investigations for suspected breach of the 90-night rule. Notices were issued to 22 properties, with a further 36 in draft, relating to the same period.
In 2024, 469 new short-term letting investigations were opened, with 2 properties being served notice by the council.
The issue is not limited to Westminster, with Tower Hamlets Borough Council investigating 24 properties in 2025, with 8 found to be in breach of the 90-night rule. In 2024, they investigated 35 properties, with three found to be in breach of the clause.
Hounslow Borough Council recorded 10 properties in breach of the rule in 2025.
A registration scheme for short-term lets will be introduced to crack down on those not complying with the 90-night rule and to ease the capital’s housing crisis.
Discussions are taking place regarding whether there will be a gradual roll-out of the property register or whether this will be introduced across England simultaneously.
Secondary legislation is set to go through parliament with details of how the scheme will work in practice.
If the property register includes a way to track the number of nights a property is used for, this will help councils to prove that a breach has occurred and therefore take enforcement action.
Commenting on the findings, Jonny Christie, co-founder of The Property Buying Company, said:
“Losing a vast number of homes to short-term lets is a significant problem nationally and particularly in London. It’s encouraging to see that discussions are in place to take steps to tackle the issue with a short-term let property register. A launch date for the registration scheme is expected to be announced this year, once the scheme has been finalised.
“If your property is registered as a residential home, where council tax applies, you can host short-term lets for up to 90 nights. If you exceed 90 nights, you must contact your local council to apply for planning permission to change your property’s use to a holiday rental or serviced apartment.”