Reference

Coverage & Limitations

What Zyfy does and doesn't cover, stated as plainly as the capabilities are. If you're evaluating Zyfy for a real integration, these are the questions worth checking before you build against a field, not after.

Postcode Intelligence

Area	Detail
Northern Ireland	BT postcodes are not supported — a separate commercial licence from NI Land & Property Services is required, which Zyfy doesn't yet hold. Returns a 422 unsupported_region error on all input modes.
Property price granularity	Postcode-level pricing isn't available everywhere — sparser areas fall back to a wider geography. signals.property.granularity tells you which level a given result came from; read it alongside trendConfidence rather than assuming exact-postcode precision everywhere.
Council tax band	Scotland is exact, sourced directly from the NRS council tax register. England and Wales are a modelled estimate, not authoritative VOA data — useful for area characterisation and lead scoring, not a substitute for a VOA lookup.
Crime data structure	England/Wales and Scotland publish crime data at different geographic granularities and on different release schedules, so category-level detail (violence, property, vehicle, etc.) is more granular in England/Wales than Scotland. Both are normalised into the same rateBand scale.
Rural/urban classification	Null for a small fraction of GB postcodes — a source data gap, not an enrichment failure.
EPC rating	England and Wales only. Scotland is unaffected in the composite scores that use it.
Radon potential	Covers Great Britain. Null for outward-code-only queries (e.g. "SW1A" rather than a full postcode).

Vehicle Intelligence

Area	Detail
MOT history	Not raw test records. Zyfy returns derived signals only — pass rate, odometer trend, defect clusters, advisory trend, fleet benchmarks — computed from the full DVSA history. Individual test line items and defect free-text are never returned.
Condition & maintenance percentiles	Benchmarked against other vehicles of the same make/model/year. Can be null shortly after a lookup, or when there isn't yet enough of that make/model/year in our dataset to benchmark against.
Data freshness	DVLA and MOT data are kept current on an ongoing basis as new records become available.
NCAP safety rating	Matched by make and year against Euro NCAP open data. Null when no match is found — not every make/model/year combination has been independently assessed.

Platform-wide

Area	Detail
enrichmentPending	A first-time vehicle lookup can return enrichmentPending: true with partial data while background enrichment completes — re-poll after the Retry-After header value rather than treating it as final. Postcode data is pre-loaded and never returns enrichmentPending.
Overage billing	None. Paid plans get a 10% grace buffer above the stated quota for genuine burst traffic; once that's exhausted, requests are hard-blocked with 429 until the period resets. The free tier has no grace buffer.
Bulk caps	Per-tier: Free and Micro can't use bulk endpoints at all; Starter 50, Pro 100, Business 250, Enterprise 500 per call. Applies to both POST /bulk endpoints and GET /postcode/within.
Shared quota	One monthly allowance covers both products — a postcode lookup and a vehicle lookup consume from the same pool.