Market rent index
GET /v1/market/rent-indexHedonic ASKING-RENT index for one postcode district, local authority or Great Britain, from portal lettings, 2022M01 = 100, with bands and SEs. This is the residential rent index; commercial_rent_index_series is the VOA one for commercial property.
Authenticate with an API key from the API & MCP Hub. The same call is available as an MCP tool at the same price.
Reference
What GET /v1/market/rent-index returns
It is validated every build against the ONS Price Index of Private Rents by local authority and NOT published in a month where the two disagree by more than a few points a year — so a missing recent month is a refusal, not an outage; say so. Asking rents, not achieved; value is an index level, never a rent. For rent LEVELS and yields use listing_market_series.
Same area and frequency rules as asking_price_index_series.
Inputs
Before you call it
- area_code
- The area code is a postcode district ("W14") with
area_typeset to district, or a local authority name ("Camden", not a GSS code) witharea_typeset to lad. No lookup is needed. An unknown area returns an error naming the nearest matches; read them back rather than guessing.
Request
Calling GET /v1/market/rent-index
curl "https://api.marketcode.ai/v1/market/rent-index?area_code=Lewisham&area_type=lad&limit=6" \
-H "Authorization: Bearer $MARKETCODE_API_KEY"Send your API key as a Bearer token. Every response carries credits_charged and credits_remaining.
Inputs
Parameters
| Name | In | Type | Required | Description |
|---|---|---|---|---|
| area_code | Query | string | No | Postcode district ("W14"), local authority NAME ("Camden") with area_type=lad, or NATIONALDefault: NATIONAL |
| area_type | Query | string | No | district | lad | nationalDefault: district |
| frequency | Query | string | No | monthly | quarterly — read provenance.pub_freqDefault: monthly |
| method | Query | string | No | hedonic_smoothed | hedonic_rawDefault: hedonic_smoothed |
| from | Query | string | No | YYYY, YYYY-MM or YYYY-Qn |
| to | Query | string | No | Last period (inclusive) |
| limit | Query | integer | No | Default: 400 |
Response
What GET /v1/market/rent-index returns for a real request
curl "https://api.marketcode.ai/v1/market/rent-index?area_code=Lewisham&area_type=lad&limit=6" \
-H "Authorization: Bearer $MARKETCODE_API_KEY"{
"country": "UK",
"query": {
"area_code": "Lewisham",
"area_type": "lad",
"frequency": "monthly",
"method": "hedonic_smoothed",
"limit": 6
},
"data": {
"area": {
"scope": "lad",
"area_key": "c0694b59-04d1-48ab-9a4c-c4f9d7b74f60",
"area_code": "Lewisham",
"area_name": "Lewisham"
},
"frequency": "monthly",
"basis": "Hedonic (mix-adjusted) index of ASKING rents from portal listings, 2022M01 = 100, smoothed toward the parent geography with posterior standard errors. Validate…",
"series": [
{
"period": "2026M03",
"period_start": "2026-03-01",
"value": 110.37210808439843,
"lo": 109.16951798868122,
"hi": 111.58794567781428,
"se_pp": 0.8548678811047612,
"inc_se_pp": 1.0646344730950843,
"yoy_pct": 0.9445566632207524,
"n_obs": 897,
"is_provisional": false
},
{
"period": "2026M04",
"period_start": "2026-04-01",
"value": 113.90924450636952,
"lo": 112.63086068539413,
"hi": 115.20213825103538,
"se_pp": 0.8806730125610661,
"inc_se_pp": 1.0667307051832329,
"yoy_pct": 3.953846881750178,
"n_obs": 897,
"is_provisional": false
},
{
"period": "2026M05",
"period_start": "2026-05-01",
"value": 105.42554586082936,
"lo": 103.07052363030782,
"hi": 107.83437716799968,
"se_pp": 1.7628262936279937,
"inc_se_pp": 1.6907054539964568,
"yoy_pct": -6.0246877053665155,
"n_obs": 68,
"is_provisional": true
},
"… 3 more"
],
"provenance": {
"source_table": "marts_facts.listing_index",
"basis": "asking_rent",
"method": "hedonic_smoothed",
"pub_freq": "quarterly",
"parent_key": "NATIONAL",
"base_period": "2023 mean",
"n_obs_total": 41207,
"n_periods": 6,
"first_period": "2026M03",
"last_period": "2026M08",
"built_at": "2026-09-05T11:16:13.107592+00:00",
"validation": "Year-on-year compared with ONS PIPR per local authority each build; the index is not written when the median absolute disagreement exceeds 4 pp."
},
"notes": [
"4 period(s) are PROVISIONAL (2026M05..2026M08): the crawl has not finished observing them — recent listings are mostly still live and live pages are under-date…",
"The pipeline judged quarterly the resolvable grain for this area (posterior SE of the monthly move > 1 pp); the monthly series is stored but noisier. Read inc_…"
],
"source": "robosapien",
"cached": true,
"time_ms": 52.9
},
"credits_charged": 0
}A real response, captured from production and trimmed: arrays to three items, long strings shortened, volatile keys dropped.
Response
Response fields
| Field | Type | Example |
|---|---|---|
| country | string | UK |
| query | object | |
| query.area_code | string | Lewisham |
| query.area_type | string | lad |
| query.frequency | string | monthly |
| query.method | string | hedonic_smoothed |
| query.limit | integer | 6 |
| data | object | |
| data.area | object | |
| data.area.scope | string | lad |
| data.area.area_key | string | c0694b59-04d1-48ab-9a4c-c4f9d7b74f60 |
| data.area.area_code | string | Lewisham |
| data.area.area_name | string | Lewisham |
| data.frequency | string | monthly |
| data.basis | string | Hedonic (mix-adjusted) index of ASKING rents fro |
| data.series | array | |
| data.series[].period | string | 2026M03 |
| data.series[].period_start | string | 2026-03-01 |
| data.series[].value | number | 110.37210808439843 |
| data.series[].lo | number | 109.16951798868122 |
| data.series[].hi | number | 111.58794567781428 |
| data.series[].se_pp | number | 0.8548678811047612 |
| data.series[].inc_se_pp | number | 1.0646344730950845 |
| data.series[].yoy_pct | number | 0.9445566632207525 |
| data.series[].n_obs | integer | 897 |
| data.series[].is_provisional | boolean | false |
| data.provenance | object | |
| data.provenance.source_table | string | marts_facts.listing_index |
| data.provenance.basis | string | asking_rent |
| data.provenance.method | string | hedonic_smoothed |
| data.provenance.pub_freq | string | quarterly |
| data.provenance.parent_key | string | NATIONAL |
| data.provenance.base_period | string | 2023 mean |
| data.provenance.n_obs_total | integer | 41207 |
| data.provenance.n_periods | integer | 6 |
| data.provenance.first_period | string | 2026M03 |
| data.provenance.last_period | string | 2026M08 |
| data.provenance.built_at | string | 2026-09-05T11:16:13.107592+00:00 |
| data.provenance.validation | string | Year-on-year compared with ONS PIPR per local au |
| data.notes | array | |
| data.source | string | robosapien |
| data.cached | boolean | true |
| data.time_ms | number | 52.9 |
| credits_charged | integer | 0 |
Fields observed in the example response above; a field the example did not exercise is not listed.
Price and licence
What it costs, and where the data comes from
Market rent index is free over MCP and over REST, and the two surfaces share one credit balance. Free calls need a signed-in account or an API key and appear in your usage, but they never touch your balance.
Credits are granted on sign-up and bought in packs; the pricing page lists every call.
Computed by MarketCode from
- Office for National Statistics
Price Index of Private Rents and geography lookups
Open Government Licence v3 · UK
- Property portals
Sale and lettings listings
Collected from publicly marketed listings · Great Britain
How the model or index is built, and where it is weak, is on the methodology page.
Related
Endpoints used with Market rent index
- Commercial rent indexFree
commercial_rent_index_seriesCommercial RENT index from the VOA rating lists — FOUR points, one per list (2010 / 2017 / 2023 / 2026), each dated at that list's antecedent valuation date (2008-04-01, 2015-04-01, 2021-04-01, 2024-04-01), with the 2010 list = 100.Named in the description - Supply-side listing statisticsFree
listing_market_seriesMonthly supply-side statistics from portal listings for one area, channel and bedroom band: listings added and reduced, reduction share (the market-temperature signal), asking price or rent median and quartiles, £/m² where a floor area is stated, new-build share, agent concentration (HHI, top-3 share), and — on rent rows — gross yield on two bases (cell rent over cell price; per-listing rent over the unit's AVM value), and on sale rows the asking-to-sold ratio and days to completion on listings the registry matched to a sale.Named in the description - Asking-price index (portal listings)Free
asking_price_index_seriesHedonic ASKING-PRICE index for one postcode district, local authority or Great Britain, from portal listings (Rightmove ~95%), 2022M01 = 100, with 80% bands and posterior standard errors, smoothed toward the parent geography.Named in the description - Commercial capital indexFree
commercial_index_seriesRepeat-sales CAPITAL index for UK commercial property, quarterly, 1995Q1 = 100.Same category - Commercial capital and rent indices for a placeFree
commercial_marketThe commercial market for a sector and a place: the repeat-sales CAPITAL index, the VOA rating-list RENT index, and the rated stock standing in the authority with its hereditament count, total and median rateable value.Same category - Index forecast h1–h7 with bandsFree
market_forecastThe published house-price index forecast for a postcode district or local authority: the last SETTLED index point as the anchor, then up to seven forecast periods with `lo`/`hi` bands, plus the method and publication grain behind them. Seven is the horizon the index publishes — nothing beyond it is offered, and a forecast is a projection of the smoothed repeat-sales index, not a valuation of any property. UK only.Same category
Glossary
Terms used here
- Local authority district (LAD): The council area a property sits in: about 360 in Great Britain, the second geography MarketCode publishes indices and rankings for.
- Hedonic index: A price index that prices the attributes of each property (type, bedrooms, size, location) so that a change in what is on the market does not read as a change in prices; the method behind the asking indices.
FAQ
Questions about Market rent index
How much does `asking_rent_index_series` cost?
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Market rent index is free over MCP and over REST, and the two surfaces share one credit balance. Free calls need a signed-in account or an API key and appear in your usage, but they never touch your balance.
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 asking_rent_index_series 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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Computed by MarketCode from Office for National Statistics price index of private rents and geography lookups and Property portals listings. Coverage is Great Britain. The methodology page describes how the model or index is built.
Does `asking_rent_index_series` 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.
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