Sourcing offmarket owners
POST /v1/sourcing/offmarket-ownersWho owns the stock in an area, ranked as an approach list: units held here, total value and equity, average and longest years held, how many of their units are on a short lease or already on the market, company status, and the signals behind the rank. Pass a `strategy` to rank the owners of only the units that preset points at — the owners of short-lease flats in a borough, say.
Same call over MCP
Owners in an area, ranked as an approach listsourcing_offmarket_ownersAuthenticate with an API key from the API & MCP Hub. The same call is available as an MCP tool at the same price.
Reference
What POST /v1/sourcing/offmarket-owners returns
COMPANIES ONLY, by construction: owners are grouped by company number, so units held by private individuals have no group to appear in. They are counted under not_itemised and never listed, and you must not attempt to identify them by other means. Report the scope.share_itemised figure so the user knows what fraction of the area the list covers.
national_portfolio reads not_available: only the in-area holding is known, and it is not the owner's whole book — do not present it as one. UK only.
Inputs
Before you call it
- postcode_district
- Give a postcode district ("SW11") or a postcode area ("SW"). Auction records carry a postcode rather than an area id, so there is no
area_idpath here and no lookup to make first.
Request
Calling POST /v1/sourcing/offmarket-owners
curl -X POST "https://api.marketcode.ai/v1/sourcing/offmarket-owners" \
-H "Authorization: Bearer $MARKETCODE_API_KEY"
-H "Content-Type: application/json" \
-d '{}'Send your API key as a Bearer token. Every response carries credits_charged and credits_remaining.
Inputs
Parameters
This endpoint takes no path or query parameters.
Request body
| Name | In | Type | Required | Description |
|---|---|---|---|---|
| lad_code | Body | string | No | A LAD GSS code, e.g. E09000032 |
| postcode_district | Body | string | No | e.g. SW11 |
| h3_cells | Body | integer[] | No | h3 r8 cells, max 500 |
| strategy | Body | string | No | Narrow to a preset's units before grouping |
| strategy_overrides | Body | object | No | |
| min_units | Body | integer | No | Default: 2 |
| limit | Body | integer | No | Default: 50 |
Price and licence
What it costs, and where the data comes from
Sourcing offmarket owners costs 2 credits per successful call over MCP and over REST, and the two surfaces share one credit balance.
The price covers licensed records in the response. A call that fails is not charged.
Credits are granted on sign-up and bought in packs; the pricing page lists every call.
Related
Endpoints used with Sourcing offmarket owners
- Build cost: index, regional factor, estimateFree
build_costBuild cost for a scheme: the sector's cost index with its 1- and 5-year movement, the regional location factor (`region`: NATIONAL, LONDON, SOUTH_EAST — an error lists what is loaded), the editorial on-cost percentages (prelims, contingency, overheads & profit, professional fees) and, given `gia_m2` and `rate_gbp_m2` (your BCIS or in-house base rate, with `rate_period` in the series' own format, e.g. 2024Q1), an estimate: the rate carried through the index to the latest period, localised, multiplied out, with totals at low / mid / high on-costs. The £/m² benchmark leg says `not_available` until a tender benchmark is loaded — no rate is invented, and nothing here is a modelled number. UK only.Same category - Construction cost index seriesFree
cost_indexConstruction cost index series for a development appraisal's cost side: `basis` is tender (tender price indices), output (output price indices), deflator (the construction deflator) or labour. Optional `sector` (residential, commercial, industrial, infrastructure, all, …), `freq` (monthly | quarterly | annual) and an inclusive period window in the series' own format (2014Q1, 2014M01, 2014). Each series carries its base period and method. UK-wide; regional factors come with the site appraisal. UK only.Same category - Adjacent parcels, owners and the combined site2 credits
land_assemblyThe parcels adjacent to one parcel and who owns each — the first question of a site assembly. Returns each neighbour with its area, land use, constraints and registered proprietor, plus a `combined` block: total area in m² and hectares, the number of distinct owners, how many neighbours already share the subject's proprietor (the parcels needing no second negotiation), how many have no linked owner, and every constraint present across the whole assembly.Same category - One parcel: owner, units, plot, constraints1 credit
parcel_lookupOne land parcel in full: its INSPIRE id, title number and OS id, area and land use, the registered proprietor where a title links, the units standing on it, plot utilisation, and every constraint flag.Same category - Site appraisal dossier5 credits
site_appraisalEverything known about ONE site, assembled and judged — the site dossier.Same category - Rated commercial stock in an authority2 credits
sourcing_commercialRated commercial stock in a local authority, filtered by sector and rateable value — the commercial sourcing lane. Each row carries its rateable value, an income-basis value, the freeholder where a title links, and any auction history.Same category
FAQ
Questions about Sourcing offmarket owners
How much does `sourcing_offmarket_owners` cost?
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Sourcing offmarket owners costs 2 credits per successful call over MCP and over REST, and the two surfaces share one credit balance. The price covers licensed records in the response. A call that fails is not charged.
How do I authenticate?
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Send your API key as a Bearer token in the Authorization header. Keys are created in the API & MCP Hub, shown once and revocable. Every response carries the credits charged and your remaining balance.
Is there an MCP version?
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Yes. The sourcing_offmarket_owners tool on the MarketCode MCP server is the same call at the same price, signed in with OAuth rather than a key, so Claude, ChatGPT, Codex and Cursor can run it in a conversation.
Where does the data come from?
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The answer is computed by MarketCode. Coverage is the UK.
Can I store or republish the results?
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The response includes records we license. Use them in your own analysis, reports and products; bulk redistribution of the raw records or building a competing dataset from them is not covered. Ask us if you need a redistribution licence.
Does `sourcing_offmarket_owners` change anything?
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No. The tool is annotated read-only on the server, so it never writes to your data or ours and an assistant can call it without a confirmation step.
Try Sourcing offmarket owners on a real address.
30-minute call. We'll provision a key and walk through the endpoint on your use case.