Double the holding cost of a second home and some owners decide it is not worth keeping. From April 2025, English councils can charge up to a 100% council-tax premium on second homes - a doubled bill - and most have. The number of recorded second homes has already started to fall. GalimAI maps the owners and companies behind that stock. This study reads the shift from that proprietary view.
What GalimAI’s own data reveals
A doubled holding cost only matters if you can see who pays it. GalimAI maps the 463,022 property-owning companies and more than 1,000,000 owners across England and Wales, each linked to what they hold and the signals around them - including the owners of second and additional homes the premium targets. The fall in second-home numbers is not an aggregate in our data; it is specific owners deciding to sell.
That is the unique value. Our own analyses show where the stock flows: the buyers most active in the last 24 months who absorb the homes that exiting owners sell, and the concentrations in GalimAI’s regional map - particularly the coastal and tourist areas where second homes and the premium cluster. The owner choosing to sell rather than pay double, and the buyer who will take it on, are both named.
For an investor that is the edge: the second-home owners most likely to list because the economics changed - and the cheapest stock to acquire - are a reachable list in GalimAI rather than a guess.
What changed: a doubled bill
From 1 April 2025, billing authorities in England can charge a council-tax premium of up to 100% on second homes - taking the bill to up to 200% of the standard charge. A second home is defined as a furnished property with no resident that is occupied only periodically. Unlike the long-term empty-homes premium, it applies immediately rather than after 12 months.
Take-up was rapid: 211 of 296 authorities (71%) reported charging the premium in 2025, most at the maximum. Listing a property for sale or letting can secure a 12-month exemption - itself a prompt to sell.
The public backdrop
The public data already shows movement: about 268,000 dwellings were recorded as second homes for council tax in October 2025, down roughly 12,000 (4.3%) on 2024 - the premium is changing behaviour at the margin. What the public data does not show is which owners and companies are selling, and where. That is the connection GalimAI’s map makes.
The most plausible mechanism
Doubling the council-tax bill raises the annual cost of holding a second home, tipping marginal owners toward selling - and the 12-month exemption for a property listed for sale gives them a direct reason to do so. The fall in recorded second homes from 2024 to 2025 fits that timing. We present this as a strong correlation with a clear mechanism, not proof that the premium alone explains any single sale - mortgage costs and the furnished-holiday-let tax changes press the same owners.
Sources
The proprietary figures in this study (the 463,022 companies, 1,000,000+ owners and the distress signals) are GalimAI first-party data. The public background figures are drawn from:
- House of Commons Library - why am I paying a council tax premium on my second home?
- GOV.UK - council taxbase 2025 in England (second homes)
Frequently asked questions
What does GalimAI's own data add here?
It names the second-home owners. GalimAI maps 463,022 property companies and 1M+ owners with their holdings, so the owners facing a doubled council-tax bill - and most likely to sell - are visible rather than aggregated.
What is the second-home council-tax premium?
From 1 April 2025, English councils can charge up to a 100% premium on second homes - up to 200% of the standard bill. A second home is a furnished property with no resident, occupied only periodically; 211 of 296 councils charged it in 2025.
Is it making owners sell?
Recorded second homes fell about 12,000 (4.3%) from 2024 to 2025, and listing for sale earns a 12-month exemption - a strong correlation with a clear mechanism. Mortgage costs and other tax changes also matter.
How can investors use this?
The second-home owners most likely to sell, and the cheapest stock to acquire, are a reachable list of named owners in GalimAI.