Our checking method

How we check restriction information

We combine open postcode coordinates, official analytical supply zones and dated water-company notices. The result remains an estimate until the property’s supplier is confirmed.

01

Locate the postcode

The full postcode is sent to Postcodes.io, which returns an approximate point derived from open postcode data. We do not store the postcode or put it in a page URL.

02

Compare supply boundaries

The point is compared locally with Environment Agency and Dŵr Cymru Water Resource Zones, revised EA 2025-10-08; Dŵr Cymru 2025-09-22. Suppliers within 750 metres of a boundary remain possible candidates.

03

Check restriction sources

Water-company notices provide the restriction status. Water UK’s national overview is a cross-check; a conflict stays visible instead of being normalised away.

04

Test against the original sources

The operational audit re-reads all 23 test postcodes, downloads the current Environment Agency and Dŵr Cymru boundary files, and checks the current supplier notices, including lifted restrictions. Property-level claims require a current supplier checker; a retired endpoint cannot establish current status. A changed or unreachable source cannot produce a clean audit.

05

Keep the limits visible

The restriction snapshot was reviewed 23 September 2026 and expires 26 September 2026. Sources that block automated access require a browser check. Multiple suppliers, partial bans, missing data and failed lookups never become a definitive answer.

Result contract

What each answer can and cannot mean

Likely affected
One likely supplier contains the postcode point and reports a restriction across its whole supply area.
Several suppliers possible
The postcode point is close to or overlaps an analytical boundary, so every candidate and its status is displayed.
No restriction found
The likely supplier was not in the dated national restriction register. This remains an estimate, not a legal assurance.
Cannot complete
Failed postcode services, expired restriction sources and unmatched boundaries return no yes-or-no conclusion.

Privacy

We do not keep your postcode

Need to confirm the supplier first? Use the independent industry lookup, then check the restriction directly with that company.

Find my supplier ↗National restriction overview ↗Supply-zone dataset ↗