A total of 2,712 properties under Westminster City Council are currently being investigated for potential unlawful short-term letting, according to the latest available data as of 30 March 2026. The figures highlight ongoing enforcement activity in one of London’s most heavily regulated rental markets, particularly as authorities prepare for a new registration system for short-term lets.
The upcoming scheme is expected to bring greater oversight to the sector, with the aim of improving transparency and helping councils better track compliance with existing rules, including the well-known 90-night limit.
Rising enforcement activity in Westminster
Last year, Westminster City Council opened 499 investigations into suspected breaches of short-term letting rules. These cases largely relate to concerns that properties may have exceeded the legal limit of 90 nights per calendar year, which applies to residential homes in London unless planning permission is granted for alternative use.
Under current regulations, property owners can let out their homes on a short-term basis for up to 90 nights annually. If they wish to exceed this threshold, they must apply for formal approval to change the property’s use classification.
During the same period, enforcement activity led to 22 properties receiving formal notices, while a further 36 cases were prepared for potential action. This compares with 469 investigations opened in 2024, alongside two properties being served notices, suggesting a gradual tightening in enforcement outcomes.
What the 90-night rule is designed to do
The 90-night rule was introduced to help protect long-term housing supply in London, where pressure on available homes remains high. It is also intended to reduce disruption in residential neighbourhoods caused by frequent short-term guests, such as noise complaints, waste issues, and general community disturbance.
The rule ensures that properties registered as residential homes are not converted into near full-time holiday accommodation without oversight from local planning authorities.
Research compiled by The Property Buying Company, based on Freedom of Information requests to London boroughs, shows how enforcement varies across different areas.
For example, Tower Hamlets London Borough Council investigated 24 properties in 2025, with eight confirmed as breaching the rule. In the previous year, 35 properties were examined, with three found to be in breach. Meanwhile, Hounslow London Borough Council recorded ten confirmed breaches in 2025.
National short-term let register plans
Alongside local enforcement, discussions are progressing around the introduction of a national short-term let registration scheme. The proposed system would require property owners to register homes used for short-term stays, giving councils a clearer picture of how properties are being used across their areas.
The register is expected to improve compliance monitoring by allowing authorities to track usage more effectively, including how many nights a property is rented out. This would make it easier to identify potential breaches of the 90-night rule and take enforcement action where necessary.
Although a launch date has not yet been confirmed, the scheme is expected to be introduced through secondary legislation, with further details to be confirmed in due course. It is also still unclear whether the system will be rolled out simultaneously across England or introduced in stages.
Industry reaction and concerns
Jonny Christie, co-founder of The Property Buying Company, said the scale of short-term letting activity being investigated reflects a wider national issue, particularly in London where housing demand is already under pressure.
He noted that while short-term lets can provide flexibility for property owners, exceeding the permitted limit without approval can reduce the availability of homes for long-term renters.
He also highlighted that clearer regulation through a registration system could help bring more structure to the market and support councils in enforcing existing rules more effectively.
Why it matters for the housing market
The growing number of investigations suggests that enforcement of short-term letting rules is becoming more active, particularly in central London boroughs. With thousands of properties now under review, local authorities appear to be taking a firmer stance on compliance.
At the same time, the introduction of a national register could mark a significant shift in how the sector is managed. By improving visibility over how homes are being used, councils may be better positioned to balance tourism demand with long-term housing needs.
For now, Westminster’s figures underline the scale of activity already taking place in the capital, and the increasing focus on ensuring properties are used in line with planning regulations.
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