Chimnie and Idox both deal in UK property and planning data, but they've built their businesses around different buyers and different parts of the data chain. Idox is a GovTech company that provides software and data services to local authorities, including the planning application systems that most councils use to manage the planning process. Chimnie is a property data bureau that aggregates property intelligence from hundreds of sources - including planning data - and delivers it via API to insurers, lenders, and proptech firms.
This comparison looks at what each provider delivers, where they overlap on planning data specifically, and which type of buyer each one serves.
Who is Idox?
Idox plc is a UK-listed software company (AIM: IDOX) headquartered in London, with revenue of £87.6 million in its most recent fiscal year. The company's largest division is Land, Property and Public Protection (LPPP), which provides the software systems local authorities use to manage planning applications, building control, environmental health, and licensing.
Idox's Uniform platform is the market-leading planning case management system used by a large proportion of UK local planning authorities. When a homeowner submits a planning application to their council, there's a good chance it's being processed through Idox software. The company also operates the Public Access portals that let citizens search and view planning applications online.
Through its Idox Geospatial division (formerly Aligned Assets and other acquired companies), Idox offers location data services, including planning applications data, property attributes, and over 300 layers of open data via theMapCloud platform. This division supplies geospatial data to commercial customers through managed API services, WFS, WMTS, and WMS feeds.
Idox's pricing is enterprise-oriented and not published. Contracts for geospatial data services are negotiated individually, and the primary customer base for the LPPP division is public sector rather than commercial.
PropertyData property market analytics website screenshot
Who is Chimnie?
Chimnie was founded by Jon Francis, formerly of Google's innovation team, to make UK property data more accessible. The company operates chimnie.com as a B2B property data bureau for insurers, lenders, and proptech firms, and chimnie.co.uk as a free consumer property research site with over 150,000 users.
Chimnie's REST API covers 35 million UK residential properties and returns over 500 attributes per property. These span EPC data, flood risk, subsidence, conservation areas, listed buildings, rebuild cost estimates, automated valuations, and structural characteristics. Crucially, Chimnie is also completing a two-year national ingestion of planning permission data from every UK local authority, standardised into a consistent schema. This dataset is launching imminently.
Pricing is published: residential lookups from £0.05 to £0.15 per property, commercial at £0.45, with volume discounts via ratecard.
The planning data overlap
Planning data is where these two providers are most directly comparable, so it's worth examining in detail.
Idox's planning data
Idox is closer to the source of planning data than almost anyone else in the UK. Its Uniform platform processes planning applications for a large share of UK local authorities, meaning the data originates in Idox systems before it appears anywhere else. Through Idox Geospatial, some of this planning data is made available to commercial customers via API and data feeds.
The challenge with Idox's planning data is coverage and standardisation. Each local authority runs its own instance of Uniform (or a competing system from NEC, Civica, or others), with its own configuration, classification schemes, and data quality standards. Idox can access planning data from its own customers, but it doesn't necessarily have standardised coverage across every UK local authority, and the data formats can vary between councils.
Idox Geospatial's theMapCloud platform offers planning applications data as one of over 300 data layers, accessible via managed API services. For customers who need planning data alongside other geospatial layers - land use, flooding, environmental designations - this is a useful integrated offering.
Chimnie's planning data
Chimnie has taken a different approach: ingesting planning permission data from every UK local authority over two years, regardless of which software system the council uses. The key difference is that Chimnie standardises all planning records into a single consistent schema, making it possible to query planning data nationally with uniform field definitions and classification codes.
This means Chimnie's planning dataset captures extensions, loft conversions, change-of-use applications, outbuilding work, and other modifications across every council in the UK, in a format that can be queried programmatically at scale. For anyone building risk models or analytics that need national planning coverage, the standardised approach matters.
The planning data is linked to individual properties via UPRN, so a single API call to Chimnie can return the property's characteristics, risk scores, valuation, and planning history together. This integrated response is designed for automated workflows rather than manual lookup.
Beyond planning data
While planning is the overlap point, Chimnie offers a much broader property data product than Idox Geospatial.
Property attributes and risk
Chimnie returns over 500 attributes per property, including structural characteristics, energy performance, multiple flood risk indicators, subsidence, tree-fall risk, roof condition (satellite-derived), solar panels, garden boundaries, conservation status, and listed building flags. Idox Geospatial offers property attributes as part of theMapCloud, but the depth per property is not comparable to Chimnie's specialist property intelligence product.
Automated valuations
Chimnie provides the UK's only free AVM, with UPRN-based lookups at zero cost and separate listing and sale price models. Idox does not offer property valuations.
Rebuild cost estimates
Chimnie provides rebuild cost estimates with confidence intervals, finish-quality segmentation, and decomposed materials and labour breakdowns. This is specifically designed for insurance underwriting. Idox does not offer rebuild cost data.
GovTech and local authority software
Idox's core business is software for local government. Planning case management, building control, environmental health, licensing, elections - these are products Chimnie doesn't offer and has no reason to. For a local authority looking for a planning management system, Idox is the obvious vendor. For a proptech firm looking for planning data to feed into a product, Chimnie's API is the more practical route.
Pricing and access
Chimnie publishes its pricing: £0.05 to £0.15 per residential lookup, £0.45 for commercial. Full API documentation is available without a sales call, and there's a free trial to test the data.
Idox Geospatial's pricing is negotiated per customer. The sales process is enterprise-oriented, and data services are typically sold as managed contracts rather than self-service API access. For large organisations with established procurement processes, this is standard. For smaller firms or developers evaluating planning data options, the barrier to entry is higher.
Where Idox is stronger
Idox is closer to the source of planning data than any other commercial provider. If you need the most current planning application data from councils that run Uniform, Idox has an inherent advantage - the data is generated in its own systems. For local authorities themselves, Idox's planning management software is the core workflow tool, and the data services sit naturally alongside it.
The breadth of Idox Geospatial's data layers - over 300 including land use, environmental designations, boundaries, and infrastructure - is useful for applications that need geospatial context beyond property-specific data. For GIS professionals, planners, and organisations that think in spatial layers rather than property-level lookups, theMapCloud's approach is familiar and well suited.
Idox's position as a public sector software provider also gives it relationships with local authorities that commercial data providers can't easily replicate. If your business involves working alongside local government planning departments, Idox is part of that ecosystem.
Where Chimnie is stronger
For property-level intelligence delivered via API, Chimnie is the stronger product. Over 500 attributes per property, published pricing, self-service access, and a modern REST API make it the practical choice for insurers, lenders, and proptech firms who need property data at scale.
The standardised national planning dataset - covering every UK local authority in a single schema - addresses a gap that Idox's council-by-council approach doesn't fully close for commercial data buyers who need consistent national coverage.
Rebuild cost estimates, the free AVM, and the full suite of risk and environmental data are products that Idox simply doesn't offer. For insurance and lending use cases, this is the data that directly feeds pricing and underwriting decisions.
The consumer platform at chimnie.co.uk, with over 150,000 users, provides ground-truth validation of property data that improves the dataset continuously. This homeowner feedback loop is a quality advantage that enterprise data platforms don't replicate.
Chimnie website homepage screenshot
Who should choose which
Local authorities and public sector organisations need Idox for planning management software. That's a different buying decision from property data procurement.
Insurers, MGAs, and lenders who need deep property data - risk scores, valuations, rebuild costs, planning history, EPC, structural attributes - should use Chimnie. The data is deeper per property, the pricing is transparent, and the API is designed for automated underwriting pipelines.
Proptech firms and planning analytics companies that need national planning data in a standardised schema should evaluate Chimnie's planning dataset once it launches. For applications that need planning data layered with 300+ geospatial datasets in a GIS context, Idox Geospatial's theMapCloud is worth considering.
For commercial organisations that need property-level planning intelligence integrated with valuations, risk scores, and property attributes in a single API call, Chimnie is the more practical route.
Conclusion
Idox is a GovTech company that runs the planning systems many UK councils depend on, with a geospatial data division that offers planning and location data to commercial customers. Chimnie is a property data specialist that has built a national planning dataset by ingesting records from every UK local authority and combining them with 500+ property attributes, valuations, and risk data in a single API.
They overlap on planning data but serve different markets. Idox is strongest in public sector software and geospatial data layers. Chimnie is strongest in property intelligence for insurance, lending, and proptech - with planning data as one component of a much broader property data product.
