Monthly market index UPM-LON-SLI-2026-09

The London Short Let Index

A monthly measure of future calendar unavailability across tracked short lets within ten kilometres of central London, with professional rate evidence reported separately.

Geography
Central London · 10 km radius
Measure
Share of observed calendar dates unavailable
Release cycle
Monthly · fixed method

01

Current evidence

Market snapshot

58%

Observation date through day 90

Whole tracked market

£222

Median nightly rate

Professionally priced portfolios · day 0 through day 30

80%

Peak date unavailable share

Friday 4 September

2,402

Unique homes in the reading

22 contributed valid price observations

02

Comparative view

What the latest reading shows

Calendar unavailability by horizonNear term unavailability was higher than it was further through the observed window. This measure includes bookings and owner blocks.
Day 0 to 30 window70%
Day 0 to 90 window58%
Peak date80%

Friday 4 September

How unavailability changes through the windowArchived supporting cut from the 12 August observation window. Each bar is the mean unavailable share within that earlier part of the forward calendar.
Days 0 to 773%
Days 8 to 1455%
Days 15 to 2154%
Days 22 to 3061%
Days 31 to 6051%
Days 61 to 9039%

03

Reading detail

Availability, price and sample depth

The September headline cleared the full publication gate across a much deeper sample. The archived August curve remains visible as historical context rather than being rewritten with the new headline.

What cleared the September gate

The daily sample remained above the publication threshold across every date in the current reading.

Unique homes
2,402Deduplicated across the ten kilometre footprint
Minimum daily sample
2,347Lowest valid home count across the current window
Dates clearing the gate
31/31Every near term date met the sample threshold
Fully unavailable dates
0No date was treated as completely unavailable

Professional price evidence

Price evidence uses 22 professionally priced homes and is kept separate from the wider availability sample.

Median daily rate
£222Published September index rate
Professionally priced homes
22Separate price population
Priced dates
31/31Every near term date supplied a valid daily median
Fixed London footprint
10 kmCentred on the same London reference point each month

04

Published data

Monthly index series

Each release is appended to this table using the same geography, freshness rule and minimum sample threshold. Published rows are not silently revised.

London Short Let Index monthly readings
ReadingDay 0 to 30 unavailableDay 0 to 90 unavailableProfessional median rateObserved
September 202670%58%£2222 September 2026
August 202661%50%£17612 August 2026

05

Data coverage

From the UK corpus to one London reading

The London index uses only the fresh, deduplicated homes that clear its fixed central footprint and daily sample gate. The wider warehouse is shown to document provenance, not to inflate the local sample.

10.36M

Night-level records

Observed availability states in the research warehouse

2.07M

Priced night records

Rows carrying a usable nightly price observation

120,143

Listing profiles catalogued

Discovery coverage before freshness and market-level deduplication

99.6%

Profiles geocoded

119,707 profiles with usable coordinates

Warehouse coverage spans 4 June to 15 August 2026. Profile counts describe the UK discovery corpus, not active supply in this market; every published index applies its own geography, freshness, duplicate and minimum-sample rules. The September headline and gate metrics use the 2 September window. Supporting curve cuts use the archived 12 August window, and the August release remains visible rather than being rewritten.

Download the London seriesCSV · monthly readings · CC BY 4.0Download the London chartSVG · publication ready · CC BY 4.0

06

Transparency

Methodology and publication notes

The index uses the latest valid availability observation for each deduplicated short let in the fixed central London sample. The primary window runs from the observation date through day 30 inclusive, covering 31 calendar dates. Unavailable percentages and professional rate evidence are calculated independently.

  1. Fixed central London footprint

    Every release uses the same ten kilometre radius centred at 51.5074, -0.1278.

  2. Deduplicated tracked supply

    Duplicate listings are collapsed before calculation so the same home cannot inflate the sample.

  3. Availability boundary

    Unavailable nights may be booked, owner blocked or otherwise restricted. They are not confirmed occupancy.

  4. Samples published

    The current reading contains 2,402 deduplicated homes, with a minimum of 2,347 valid homes on every observed date.

  5. Separate price population

    Unavailable shares cover the wider valid sample. The £222 rate uses 22 professionally priced homes only.

  6. Comparison boundary

    The sample expanded from 17 homes in August to 2,402 in September, so the difference between releases is not a pure demand trend.

  7. Publication threshold

    The rate is published only when at least five priced listings contribute valid daily medians on at least 20 of the 31 dates from day 0 through day 30.

Supporting publications

Market ReportsAirbnb and short let management in LondonLondon 90 day rule owner guideLondon property guidesBristol Short Let IndexNorth Wales Holiday Let IndexSeptember London detailed data

Property owners

Assess an individual London property

The index is a market-level signal. A property forecast can account for location, size, finish and the intended letting strategy.

Value my propertyExplore London short let management