Open the hosted link in Safari on the event iPad while connected to Wi-Fi. Leave the page open until the status says Ready for offline use. Open a constituency and its MP portrait, search a full postcode, then disconnect and reload to check that all three still work. Repeat on each device. Browser storage can be cleared or evicted; check again before every session. Private browsing is unsuitable for persistent storage. Reconnect if the offline download is incomplete.
The map covers 632 Great Britain Westminster constituencies. ElectraLink’s workbook received 15 September 2026 contains 2,837 postcode districts and 121 postcode areas. Northern Ireland is absent. The source does not specify its reporting period. Values are electricity meter points (MPANs), not households or sites. “Smart” is the source classification, not a test of communication status.
For each district, smart and non-smart counts are allocated to the seats it touches using each seat’s share of live postcodes in that district. The ONS Postcode Directory (May 2026) provides 1,746,976 live GB postcode mappings to the July 2024 constituencies. The same weights apply to domestic, SME and industrial/commercial segments. Counts remain unrounded during calculation. Coverage is smart ÷ (smart + non-smart), not an average of percentages.
The method assumes uniform meter density and coverage within each district. Postcodes are not weighted by households, businesses or meter points. Business meter distributions may differ substantially. Constituency values are estimates; this is not an exact address-level allocation or a statistical confidence interval.
The workbook marks unavailable values as −1. They are never treated as zero or inferred from postcode-area residuals. A constituency segment with any missing or suppressed contributing district has a Partial status. Its displayed counts and coverage include published contributions only. Availability percentages measure postcodes, not meter points. Such seats are excluded from rankings; equal coverage at one decimal place shares a rank.
The GB benchmark uses published postcode-area counts. Some source districts have no live-postcode match and cannot be allocated to seats, so summed constituency counts do not equal the GB total. The CSV includes segment status and postcode availability alongside estimates. No raw ElectraLink workbook or district-level meter data is included in the site.
Map geometries are ONS July 2024 generalised boundaries; OS Election Maps is the requested reference, not the source of a copied live tile service. Names, party and official portraits are from the UK Parliament Members service, retrieved 16 September 2026. Seats without a current member are shown explicitly.
Contains OS, Royal Mail and National Statistics data © Crown copyright and database rights 2026. Basemap © OpenStreetMap contributors / Protomaps. Member data: Open Parliament Licence. Official portraits: House of Commons and named photographers, portrait credits, CC BY 3.0, compressed for display. No MP endorsement is implied.