The findings come from TwentyCi’s Q2 2026 Property & Homemover Report.
The report pointed to a heightened risk across mortgage pipelines, which included down-valuations, stalled cases, renegotiations, and higher fall-through rates.
In the space of 12 months, this gap has doubled, now up from 5.7% in Q2 2025.
The share of properties listed 10% or more above true market value also rose, up 9.7% year-on-year.
The East of England recorded the largest increase nationally, as overpricing volume was up 19.3% year-on-year.
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Outer London followed with a rise of 17.8%, while the South East saw an increase of 16.7%.
However, Inner London and the North East experienced price corrections that aligned more closely with actual market values.
Risk of overoptimism
Headline market data is often anchored to listing prices. The report noted this presented an overly optimistic picture of market conditions.
Inflated listing prices skewed automated lending metrics and underwriters faced additional work reconciling asking prices with independent valuations.
Colin Bradshaw, CEO of TwentyCi, said: “While a busy market is always welcome, this widening gap between what sellers want and what properties are actually worth should serve as a clear warning sign for the lending community.
“If listing prices drift too far from independent AVM values, down-valuations will inevitably spike. For lenders, this means clogged pipelines, increased administration, and higher fall-through rates. Relying solely on listing-led indicators right now is a risk; robust, independent valuation data has never been more critical to protect lending security.”
