What is the difference between API calls and reveal credits?

API calls are a monthly quota used for searches, lookups, and property data. Reveal credits are a separate £ wallet used to reveal sensitive listing data (UPRN + full address + event timeline) at £0.20 per first reveal. Every paid plan refills both pots monthly.

How much does the Homedata API cost per call?

On the Starter plan (£49/mo, 2,000 calls) each call costs approximately 2.45p. On Growth (£149/mo, 10,000 calls) it's 1.49p. On Pro (£349/mo, 50,000 calls) it's 0.70p. On Scale (£699/mo, 250,000 calls) it's 0.28p.

Do reveal credits expire?

No. Reveal credits never expire. They accumulate in your wallet across billing periods. An already-revealed listing is free forever for your organisation — you only pay £0.20 for the first reveal.

What are the rate limits per plan?

Free: 2 requests/sec. Starter: 5/sec. Growth: 10/sec. Pro: 20/sec. Scale: 40/sec. Enterprise: custom. Monthly quotas reset on plan renewal.

Pricing & Rate Limits

Two independent pots: a monthly API call quota for searches and lookups, and a separate reveal credit wallet for revealing sensitive listing data (UPRN + full address + event timeline). Every paid plan refills both. Credits never expire.

Pot 1 — API calls

Monthly quota

Searches, lookups, property data, risk, schools, comparables. Most endpoints cost 1 call. Premium endpoints with real licensing costs use weights of 2, 5, or 10. Resets on plan renewal.

Pot 2 — Reveal credits

£ wallet · never expires

Reveal UPRN + full address + event timeline for a listing. Flat £0.20 per first reveal. Already-revealed listings are free forever per org. Granted monthly with every paid plan; one-off top-up packs available.

What each plan grants

Every paid tier issues monthly reveal credits matching the plan price (£1 of credits per £1 paid). Calls and credits are independent — a Growth customer with 9,000 calls left can still run 745 reveals from their £149 wallet.

Plan	Monthly	Calls/mo	Reveal credits/mo	Cost/call	Rate limit
Free	Free	100	—	—	2 req/s
Starter	£49/mo	2,000	£49	2.45p	5 req/s
Growth Popular	£149/mo	10,000	£149	1.49p	10 req/s
Pro	£349/mo	50,000	£349	0.70p	20 req/s
Scale	£699/mo	250,000	£699	0.28p	40 req/s

Call weights by endpoint

Most endpoints cost 1 call. Address endpoints carry Royal Mail PAF / Ordnance Survey licensing; comparables runs PostGIS spatial joins; HMLR confirmed sales (/lr_sales/) carries Land Registry licensing.

2 calls

GET /api/address/find/

Address autocomplete — text → up to 8 UPRN suggestions. Search licensing.

2 calls

GET /api/address/postcode/{postcode}/

All UPRNs + addresses at a postcode. PAF + search licensing.

5 calls

GET /api/address/retrieve/{uprn}/

Full enriched address — structured lines, coordinates, building components. Royal Mail PAF + OS licensing.

5 calls

GET /api/lr_sales/?uprn=X

HM Land Registry confirmed sale completions for a property — txid + sold_let_date + sold_let_price per row. Accepts ?uprn= or ?sale=. HMLR licensing.

5 calls

GET /api/solar-assessment/{uprn}/

Solar PV suitability — roof orientation, pitch, shading. External MCS data.

10 calls

GET /api/comparables/{uprn}/

AI-ranked comparable sales within radius. PostGIS spatial query + ranking model.

1 / row

GET /api/live-listings/search/

Lead Source — search live UK listings by area + filters (DOM, reductions, status, price band, bedrooms, etc.). 1 call per listing returned. Default page_size=30 ⇒ 30 calls; max 200/page on Pro+. UPRN + full address + sensitive event dates redacted unless revealed via /api/listing-address/.

1 / 10 rows

POST /api/listings/export

Bulk export (Growth+). 1 call per 10 rows returned. Per-request caps: Growth 1,000 / Pro & Scale 5,000.

1 call

Everything else

Property record & add-ons (rooms, roof, garden, parking, dimensions, land, construction, EPC, council-tax, valuations, LR titles), risk (flood, radon, coal, landfill, air, noise, invasive plants), demographics, deprivation, postcode-profile, schools, crime, broadband, boundaries autocomplete, planning search, price-trends/distributions/growth.

Typical workflow: address/find (2) → address/retrieve (5) → property record (1) = 8 calls to go from a typed address to a fully populated form. Every response includes an X-Call-Weight header.

Reveal credits — what they cover

Three endpoints debit the reveal-credit wallet. Each is flat £0.20 per call. Listings already revealed by your org are free forever.

Reveal £0.20

POST /api/listing-address

Reveal UPRN + full structured address + complete event timeline (Added → Reduced → Under Offer → Sold STC → Completed → Withdrawn) for a listing. Body: {"listing_id":"…"}. Free re-fetches per org. 404/422 errors are never charged.

Reveal £0.20

GET /api/property_listings/?uprn=X

Every listing ever created for a UPRN — every sale and every rental, going back as far as the data exists. One row per listing with sale ID, agent, status, lifecycle dates.

Reveal £0.20

GET /api/property_sale_events/?sale=Y

Event-by-event timeline for a specific sale — same data bundled inside /api/listing-address, keyed by sale ID instead of listing UUID. Accepts ?sale= or ?listing=.

Sale flow chain: /property_listings/?uprn=X (£0.20) returns sale IDs → /property_sale_events/?sale=Y (£0.20) returns the event timeline → /lr_sales/?uprn=X (5 calls) returns HMLR-confirmed completions. Or reveal everything for one listing in a single call: POST /api/listing-address (£0.20).

One-off credit top-ups

Run out mid-month? Top up the reveal-credit wallet without touching your subscription. Bigger packs get bigger discounts — credits never expire.

Pack	Price	Reveals @ £0.20	Effective discount
Starter pack	£10	50	—
Growth pack	£40	250	~20% off
Pro pack	£140	1,000	~30% off
Scale pack	£300	2,500	~40% off

Rate limits

Per API key, per second. Exceeding the limit returns HTTP 429 — requests are not queued, retry with backoff.

Plan	Requests/second	Requests/minute
Free	2 req/s	120/min
Starter	5 req/s	300/min
Growth	10 req/s	600/min
Pro	20 req/s	1200/min
Scale	40 req/s	2400/min

Retry strategy: On a 429, wait for the Retry-After header (seconds) before retrying. For batch jobs, pace requests under your tier's per-second cap.

Billing semantics

Call quota resets on plan renewal. Reveal credits never expire and roll over forever.
404 / 422 errors are never charged on credit endpoints. Successful 200 responses debit £0.20.
Already-revealed listings re-fetch free — pass the same listing_id with a new Idempotency-Key and the response returns with "charged": false.
Mid-cycle plan upgrades grant pro-rata credit — pay the prorated price difference, get the prorated credit difference. Downgrades keep existing balance and apply the new lower grant on next renewal.
Insufficient credits return HTTP 402 with required and available in the body (in pence).
Live usage and balance visible any time in the Developer Dashboard.

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Free tier — 100 calls/month, no credit card. Upgrade when you need more.

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Homedata API Scientific, granular measurements

Homedata API billing is fully transparent — every endpoint publishes its call weight upfront, and your Developer Dashboard shows real-time usage against your monthly quota and reveal credit wallet.

Structured as JSON · queryable by UPRN or postcode · ready to embed in any application

Exact measurements

Real values — distances, concentrations, counts — not rounded ratings

29M+ UK properties

Every address queryable by UPRN or postcode

REST API

JSON responses, OpenAPI docs, sandbox — first call in under 5 minutes

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Free tier: 100 API calls/month across all endpoints, no credit card required. Paid plans from £29/month for production use. Compare plans →

Sources

[1] Homedata pricing page