Transparency
Sources & methodology
Last updated 7 September 2026
SigInfo finds postcodes and places across seven countries and brings useful public radio, terrain and infrastructure context onto the page. UK results can include MastData survey readings and aggregate mast counts. Every country can show measured elevation, current conditions and communications structures recorded in OpenStreetMap. Values are labelled with their source and limitations.
Coverage
Regulators, public map services and network operators publish their own predicted coverage. Their models, update schedules and presentation differ. SigInfo links to those sources and does not rank networks for commission. Coverage maps are guidance: buildings, terrain, devices, network load and maintenance can affect service.
| Information | Source and use |
|---|---|
| UK postcodes, towns, cities and administrative areas | Postcodes.io, using ONS and Ordnance Survey Open Names data. UK place suggestions and submitted searches are requested from this service. |
| International locations and submitted street addresses | OpenStreetMap Nominatim. It is contacted after a search is submitted. A legacy location page can also make one lookup for the postcode shown in its URL. It is never used for type-ahead address autocomplete. |
| Location map | OpenStreetMap. The map marks the selected postcode centre, settlement centre, submitted address or coordinates. |
| UK signal surveys and mast counts | MastData public town records. Signal readings are averages from its Android survey over a 7 km radius. Mast figures are aggregate operator records at the listed radii and can include shared infrastructure. |
| Nearby mapped communications sites | OpenStreetMap contributors, requested through the Overpass service within 5 km of the selected point. Community mapping can be incomplete or out of date, so an absent record does not prove an absent mast. |
| Elevation and current conditions | Open-Meteo. SigInfo samples elevation at the selected point and eight surrounding points to describe local relief, and shows current weather and wind. These are environmental context rather than measurements of network coverage. |
| Mobile coverage predictions | Ofcom Map Your Mobile and the linked regulator and operator services. Their predicted coverage remains on the publishers’ sites. |
| Active flood warnings | Environment Agency flood-monitoring API, loaded only when requested. No warning does not mean no long-term flood risk. |
| Line-of-sight elevation profile | Open-Meteo Elevation API. SigInfo samples the selected path, applies the entered antenna heights and calculates distance, bearing, Earth-curvature adjustment, first Fresnel-zone clearance and free-space path loss in the browser. |
Map precision
A postcode search is marked at the postcode centre. A town or city search is marked at the settlement centre. A submitted address or coordinate search uses that mapped point, with the nearest postcode supplied for the coverage checkers. The interface labels which precision is being shown.
Unavailable data
If a source fails or times out, SigInfo says that it is unavailable. It does not substitute a generated value or infer “low risk”.
Legacy location pages
Previously generated postcode URLs are kept so bookmarks and links still work. They now use one maintained template with a location map, the same sourced on-page data panels as the main search and the relevant published coverage links. Earlier deterministic signal strengths, tower counts, speeds and risk claims were not measurements and are not reused. These near-duplicate archive routes are excluded from search indexing while the useful country guides remain indexable.
Commercial links
Advertising and affiliate links are visually separated from coverage sources. Commission does not change the ordering of official checkers. Product links are general starting points; visitors must check network, device, connector and UK regulatory compatibility.
Corrections
To report a source, labelling or accessibility issue, email [email protected].