Achieved rents in prime London rose 4.6% in the year to September, the fastest annual growth in 18 months, according to LonRes. Over the same period the number of lets agreed fell by 14.9%, and the stock of homes available to rent rose by 6.9%. Rents are rising, in other words, while the market is doing fewer deals.
For a landlord, both halves of that picture matter. A rising market rewards a well-priced home; a market with more stock and fewer agreed lets punishes one that is priced on hope.
What the figures show
LonRes, whose figures were reported on 22 October, tracks achieved rents across prime London postcodes, excluding the prime fringe. It puts average rents 43.5% above their pre-pandemic level, with new lettings instructions up 3.4% on a year earlier.
Knight Frank's index, published on 2 October, shows a gentler rise in the centre and a firmer one further out. Average rents in prime central London rose 1.3% in the year to September and 1.8% over the last six months; in prime outer London they rose 3% over the year and 2.3% over six months. In both cases the six-month rise was the fastest since January 2024. Knight Frank counted 5.6 prospective tenants for every new property in prime central London in the three months to September, the highest in four years, and 8.9 in prime outer London.
Across London as a whole, Zoopla's September report put annual growth in new-let rents at 2.9%, up from 1.7% a year earlier, with 6% fewer homes available to rent than a year before and 13% fewer in inner London.
Why the indices differ
The figures measure different things. LonRes records rents achieved on prime lettings; Knight Frank's index tracks its own basket of prime homes; Zoopla covers all new lets across London. They agree on direction, rents rising and choice for tenants narrowing, but not on pace, and a landlord should be wary of anyone quoting only the highest number.
Knight Frank's Tom Bill links part of the rise to the cost of regulation and finance: "Landlords have been setting asking rents higher to reflect the increased risks they face." Borrowing has also become dearer. Bank of England data cited by Knight Frank put the average five-year fixed buy-to-let rate at 75% loan to value at 4.7% in August, against 3.88% in January.
The £100,000 line
At the top of the market, a growing share of lettings sits above an important legal threshold. LonRes reports that 36% of homes let so far in 2026 in Mayfair and St James's were let at more than £100,000 a year, and more than 20% in Knightsbridge, Belgravia and South Kensington.
Under Schedule 1 to the Housing Act 1988, a tenancy at a rent of more than £100,000 a year in England cannot be an assured tenancy, and under section 1 of the Act only an individual can hold one, so a letting to a company is not an assured tenancy either. On the face of the legislation, such lettings sit outside the assured regime that the Renters' Rights Act has reshaped, and the terms of the agreement carry more weight. Whether a particular tenancy falls inside or outside the regime should be checked with a solicitor, not assumed.
Pricing a let this winter
- Price on achieved rents, not asking rents. With more stock on the market and fewer lets agreed, a home asking above the evidence is likely to sit while better-priced homes let.
- The advertised rent is the rent. For assured tenancies, the advert must state the rent and landlords cannot invite or accept offers above it, so the figure chosen at launch has to be right.
- Increases come once a year. For assured tenancies, rent increases now go through the statutory section 13 process, no more than once a year, so the starting rent matters more than it used to.
- Watch the void. A month empty costs roughly 8% of a year's rent; a rent pitched slightly lower that secures a good tenant quickly can be worth more over the year.
The Budget is on Wednesday 28 October. Knight Frank notes speculation about capital gains tax and about applying National Insurance to rental income; we will not guess at the outcome, and will write about any change once the detail is published.
Dolce Vita handles lettings and sales across the UK from Mayfair, and helps clients buy abroad through partner agencies. If you would like to know what your home should let for this winter, Request a lettings valuation; we acknowledge the same working day and return a written valuation within 24 to 48 hours.
Chris Dawson, Co-Founder
Sources: LonRes, prime London sales and lettings figures for September 2026 (via Property Industry Eye, 22 October 2026). Knight Frank, "Prime London rents rise as tenants feel the pre-Budget squeeze", 2 October 2026 (including Bank of England mortgage rate data). Zoopla, Rental Market Report, September 2026, 14 September 2026. Housing Act 1988, section 1 and Schedule 1, paragraph 2 (legislation.gov.uk). gov.uk, "Renters' Rights Act: an overview for landlords".