One in four properties in Britain sits on the coalfield, according to the Mining Remediation Authority. That is the body most conveyancers still call the Coal Authority: it changed its name on 29 November 2024, with its statutory duties under the Coal Industry Act 1994 unchanged. The search it sells, the CON29M, is still the standard coal mining search in a residential purchase.
Coal is one of three ground and water risks that turn up in conveyancing, survey and underwriting files. Flood risk and natural ground instability are the other two, and each has its own official source, its own report and its own blind spots.
So which check answers which question, and where does area-level data fit before you order anything?
When do you need a coal mining search?
You need one when the property is within a coalfield area. The Mining Remediation Authority's own guidance describes the CON29M as "essential prior to the completion of a house purchase if the property is within a coalfield area."
The Law Society publishes the CON29M form and three-part guidance notes, last updated in May 2018 in collaboration with the then Coal Authority. The Law Society is clear that following the guidance is not mandatory and that the notes are not legal advice. In practice, most firms treat a coalfield location as a trigger and order the report as part of the search pack.
Off the coalfield, the Authority issues a No Search Certificate instead, priced at £32 including VAT for a customer-drawn boundary in its 2026 price list.
What is a CON29M coal mining report?
The CON29M is the Authority's coal mining report for residential and non-residential transactions. As of October 2026, it covers:
- Past, present and future mining. Underground and opencast workings, plus known future activity.
- Mine entries. Shafts and adits, reported within 20 metres of the boundary, a distance the Authority says was agreed with the Law Society.
- Subsidence and mine gas. Claims history, surface hazards and gas emissions linked to coal mining.
- Professional opinion. A plain-English view of the risk, with advice on whether a coal mining risk assessment is needed.
A residential CON29M on the coalfield costs £50 including VAT if you draw the boundary yourself, or £60 if the Authority draws it. Most reports come back within 24 hours, with up to 72 hours in busy periods.
The Authority makes one limit explicit: the CON29M is for house purchases and should not inform a development risk assessment. If a buyer plans an extension, garage or patio in a development high risk area, the council or building control body may ask for a coal mining risk assessment from a qualified professional, and a Consultants Coal Mining Report is the Authority's product for that.
A CON29M answers the buyer's question. It does not answer the builder's.
What does the interactive map show?
The Authority's free online map, still widely called the Coal Authority interactive map, shows whether a location falls in a development high risk area and displays recorded mining information such as mine entries.
It is useful for a first look. It does not produce a report, carry an interpretation or sit on a search pack. Conveyancers who check the map and find a property just outside the high risk area should still read the coalfield boundary separately: development high risk area and coalfield are different layers.
The Propalt API answers the same first-look question in code. Its coal area lookup takes a latitude and longitude and returns whether the point sits in a coal zone, so a case management system can flag coalfield files without anyone opening the map. It is a screening result, with the limits set out below.
How do you run a flood risk check?
In England, the Environment Agency's "Check your long term flood risk" service covers four sources: rivers and the sea, surface water, reservoirs, and groundwater where data is available. Wales, Scotland and Northern Ireland have their own services through Natural Resources Wales, SEPA and nidirect.
The England data changed materially on 28 January 2025, when the Environment Agency released the new National Flood Risk Assessment (NaFRA). The Agency says as many as 6.3 million properties in England are in areas at risk from rivers, the sea or surface water, and that climate change could take this to around 8 million, roughly one in four, by the middle of the century. The service now shows potential flood depths and future risk.
For insurers and brokers, the second question is cover. Flood Re, the joint scheme between government and insurers, lets insurers pass the flood element of eligible home policies to the scheme. Eligibility rules out homes built on or after 1 January 2009, along with properties that are not in Council Tax bands A to H or an equivalent, among other criteria. Flood Re is due to leave the market in 2039, and as of October 2026 it has announced reforms including a claims cap from 2028.
A flood risk check from the Environment Agency is free, area-based and updated periodically. A flood report from a search provider interprets that data for a specific title. They do different jobs.
Flood risk also counts as material information on a sale listing. Our article on material information and property data APIs covers that duty from the data side.
What does a ground stability report add?
A ground stability report covers natural subsidence risk, which a coal search does not. The British Geological Survey's GeoSure dataset maps six hazards across Great Britain at 1:50,000 scale:
| HAZARD | WHAT IT DESCRIBES |
|---|---|
| Shrink-swell | Clay soils that expand when wet and shrink when dry |
| Landslides | Slope instability, including a debris flow model |
| Soluble rocks | Rocks such as chalk, gypsum and limestone that can dissolve |
| Collapsible deposits | Ground that can collapse when loaded or saturated |
| Compressible ground | Soft deposits such as peat that compress under load |
| Running sands | Sand that can flow when saturated |
GeoSure is licensed data intended for local-level use. At 1:50,000 it describes the geology of an area and does not describe the ground under a single foundation. The Mining Remediation Authority also sells a Ground Stability Report, at £87 for a residential property on the coalfield and £66 off it, both including VAT on a customer-drawn boundary.
For surveyors, the practical point is order: screen the area, then decide whether a site-specific report or an intrusive investigation is justified.
What can area-level screening tell you, and what can it not?
Area-level screening tells you whether a location falls inside a mapped zone. It does not tell you what lies under a specific building, and it carries no professional opinion.
Propalt's coal and mining data is area-level screening. It does not replace an official CON29M coal mining report from the Mining Remediation Authority, and Propalt's flood data does not replace a flood report or the Environment Agency's service.
Here is what that screening returns, using two points we queried through the Propalt MCP in October 2026 (no addresses used):
- Central Barnsley, South Yorkshire. The coal check returned
is_in_coal_zone: true. The non-coal mining check returned class "Low", with the legend "Localised small scale mining may have occurred in the area." - Camborne, Cornwall. The coal check returned
is_in_coal_zone: false. The non-coal mining check returned class "Significant", with the legend "Underground mining is known or considered likely to have occurred in the area."
The Cornish result is the useful one. A property there would pass a coal screen and sit in a significant zone for metalliferous mining. A conveyancer relying on a coal flag alone would miss it, and so would an underwriter.
A location that passes a coal check can still sit on old mine workings.
Screening at this level fits three workflows:
- Conveyancers. Flag which files need a CON29M and which need a non-coal mining search before the search pack is ordered.
- Surveyors. Pre-populate a ground and water risk section before inspection, then confirm on site.
- Insurers and lenders. Triage a portfolio or an application book by coal, non-coal mining and flood zone, then send the flagged cases for full reports.
For background on how the property identifier behind these lookups works, see What Is a UPRN?.
Coal and mining flags are one layer of a property check. Conservation areas, Article 4 directions and listed buildings are another, and our planning data API guide explains where those constraints come from.
📌 KEY TAKEAWAY
A CON29M is the coal mining search for a residential purchase on the coalfield, and it is issued by the Mining Remediation Authority. Flood risk in England sits with the Environment Agency's NaFRA data, refreshed in January 2025, while Flood Re eligibility stops at homes built before 2009. Natural subsidence risk sits in BGS GeoSure. Area-level screening tells you which of those reports a file needs, and a Cornish point that is clear of coal but in a significant mining zone shows why one flag is not enough. To screen coal, non-coal mining and flood zones across a caseload before you order searches, query them through the propalt.ai API at https://api.propalt.io or the Propalt MCP in Claude and ChatGPT.
SOURCES & DATA REFERENCES
- IOM3 (29 November 2024). 'Coal Authority changes name to Mining Remediation Authority.' Supports the name change date and unchanged statutory duties. iom3.org/resource/coal-authority-changes-name-to-mining-remediation-authority.html
- Mining Remediation Authority (accessed October 2026). 'CON29M coal mining report.' Supports report contents and the one in four properties on the coalfield figure. miningremediation.co.uk/con29m/
- Mining Remediation Authority (February 2026). '2026 mining reports prices.' Supports CON29M, Ground Stability Report and No Search Certificate prices. miningremediation.co.uk/2026-mining-reports-prices/
- Mining Remediation Authority (accessed October 2026). 'Frequently asked questions.' Supports "essential" wording, 20 metre mine entry distance and turnaround times. miningremediation.co.uk/faqs/
- GOV.UK (accessed October 2026). 'Home extensions and improvements in former coal mining areas.' Supports the free online map, development high risk areas and the CON29M not informing risk assessments. gov.uk/guidance/home-extensions-and-improvements-in-former-coal-mining-areas
- The Law Society (accessed October 2026). 'CON29 forms.' Supports the CON29M guidance notes updated May 2018 and their non-mandatory status. lawsociety.org.uk/topics/property/con29-forms
- Environment Agency (28 January 2025). 'Enhancing flood and coastal erosion risk digital services with the latest data and mapping.' Supports NaFRA release, 6.3 million and 8 million figures. environmentagency.blog.gov.uk/2025/01/28/
- GOV.UK (accessed October 2026). 'Check your long term flood risk.' Supports the four flood sources and the other nations' services. gov.uk/check-long-term-flood-risk
- Flood Re (accessed October 2026). 'Flood Re eligibility criteria.' Supports the 1 January 2009 build date and Council Tax band criteria. floodre.co.uk/faq/flood-re-eligibility-criteria/
- Propertymark (2026). 'Flood Re reforms will reshape premiums and reward resilient homes.' Supports the 2039 exit and the 2028 claims cap. propertymark.co.uk/resource/flood-re-reforms-will-reshape-premiums-and-reward-resilient-homes.html
- British Geological Survey (accessed October 2026). 'GeoSure.' Supports the six hazards, 1:50,000 scale and GB coverage. bgs.ac.uk/datasets/geosure/
- Propalt (October 2026). Coal area and non-coal mining area screening for one point in central Barnsley and one in Camborne, via the Propalt MCP (get_coal_area, get_mining_area). Supports the screening example.