Coverage Checker Resources

UK mobile coverage checker resources for IoT installers. Official operator coverage maps, Ofcom Connected Nations data, CellMapper, and why coverage maps are not sufficient for IoT commissioning.

How do I check UK mobile coverage for an IoT site?
For UK IoT sites, check coverage using official operator tools (EE, Vodafone, Three, O2 all have postcode coverage checkers), the Ofcom Connected Nations coverage dataset, and CellMapper for tower-level detail. These give indicative coverage data. Actual on-site signal depends on building materials, local terrain, antenna height and the specific hardware being installed — only a physical test with the installed router and antenna gives commissioning-grade data.

UK operator coverage checkers

OperatorURLData provided4G / 5G / NB-IoT
EEcoverage.three.co.uk2G, 4G, 5G, indoor/outdoorYes / Yes / Yes
Vodafonenetwork.vodafone.co.uk2G, 4G, 5GYes / Yes / Yes
Threecoverage.three.co.uk3G, 4G, 5GYes / Yes / No
O2www.o2.co.uk/coveragechecker2G, 4G, 5GYes / Yes / No

Ofcom Connected Nations

Ofcom publishes an annual Connected Nations report and interactive coverage map showing 4G and 5G coverage from all UK operators. The dataset is useful for understanding coverage at a strategic level and for comparing operator coverage in specific UK regions. Available at checker.ofcom.org.uk.

Limitations of coverage maps

All operator coverage maps are predictions based on modelled propagation, not measured signal. They typically assume outdoor signal at street level. They do not account for: building material attenuation, local terrain obstructions, antenna height differences, or the specific hardware characteristics of the device being installed. A site showing “good 4G coverage” on an operator map may show only -108 dBm RSRP at the router location inside the building — below the threshold for reliable IoT operation without an external antenna.

Use coverage maps for initial site qualification and operator shortlisting. Use CellTester for commissioning-grade signal data.