Key takeaways
Ofcom's Map Your Mobile tool, available at checker.ofcom.org.uk, is the UK's only independent regulator-published tool for checking and comparing mobile coverage across all four major UK networks -- EE, O2, Three and Vodafone -- at any postcode.
The tool shows two types of information: coverage (whether a 4G or 5G signal is predicted to be available outdoors and indoors) and performance (the likelihood of achieving the speeds needed for streaming video, based on real crowdsourced measurements).
Coverage and performance are not the same thing. You can have coverage -- technically a signal -- without having performance good enough to actually use apps. The performance dials, based on crowdsourced data from real users, are more useful for choosing a network than coverage maps alone.
The tool reached one million visits by May 2026. Ofcom is continuing to develop it with more granular data as part of its 'Connectivity You Can Count On' programme.
If coverage or performance is poor at your location, practical steps include checking Wi-Fi calling on your current network, comparing alternative networks using the tool, and contacting Ofcom or your provider if you believe there is a consistent gap in provision.
Reviewed: June 2026Key data
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What Map Your Mobile shows you
Ofcom's Map Your Mobile tool is built around two distinct datasets that answer different questions about mobile connectivity at your postcode.
Coverage: will I get a signal?
Coverage data shows whether a 4G or 5G signal is predicted to be available at your location, both outdoors and indoors. The tool shows results for each of the four major UK networks on an interactive map, zoomed to your postcode area. Coverage is shown as one of three states: good (signal predicted to be reliably available), variable (signal may be available but not consistently), or none (signal not predicted to be available).
Coverage data is provided to Ofcom by the mobile network operators themselves, calculated from their own signal propagation models at a 50-metre by 50-metre grid resolution for most networks (Vodafone data is currently at 100m resolution, scaled to 50m for consistency). These are theoretical predictions based on antenna power, geography, and obstacles -- not measured signal at your specific address.
Because coverage data is operator-modelled, it reflects the best-case prediction, not guaranteed performance. Signal can be reduced by trees, buildings, hills, and the specific construction of your property. Indoor coverage is particularly variable -- Ofcom notes that thick walls, energy-efficient windows and metal-rich building materials can significantly reduce the signal reaching you inside.
Performance: can I actually use apps and services?
Performance data is different in nature from coverage data. Rather than theoretical models, it is based on crowdsourced measurements -- real data from actual users running tests on their phones in your postcode district. Ofcom worked with Opensignal, a company that specialises in mobile network quality measurement, to produce the performance data in Map Your Mobile.
The performance score for each network shows the percentage of crowdsourced measurements in your postcode district that achieved Ofcom's good performance standard: download speed of at least 5 Mbit/s, upload speed of at least 1.5 Mbit/s and latency of no more than 50 milliseconds. A higher percentage means users in your area more frequently achieved the quality of connection needed to stream video, make video calls and use data-heavy apps reliably.
The performance dials are more useful than the coverage map for choosing a mobile network. Coverage shows whether signal theoretically exists; performance shows whether that signal delivers a usable connection in practice. The two do not always align.
How to use Map Your Mobile step by step
Step 1: Go to checker.ofcom.org.uk. No account or registration is required. The tool works in any browser on desktop or mobile.
Step 2: Enter your postcode. The tool will show you a map of your area with coverage data for all four major networks. You can zoom in and out and move the map to check different locations -- useful for comparing coverage at home, at work and along your commute route.
Step 3: Review coverage for each network. Look at both outdoor and indoor coverage. Indoor coverage is typically weaker than outdoor. If a network shows 'variable' or 'none' indoors at your postcode, this is a meaningful signal about likely experience at your address.
Step 4: Check the performance dials. These show the percentage of crowdsourced measurements in your postcode district that achieved good performance for each network. A network with high coverage but low performance means signal is available but congested or otherwise inadequate for real-world use.
Step 5: Compare networks. The tool shows all four networks simultaneously, making it straightforward to identify which network is likely to perform best at your specific location. Remember that performance scores cover the postcode district (outward code, e.g. SE1) rather than your specific address -- local variations can occur.
| What you see in the tool | What it means | How useful |
|---|---|---|
| Green coverage area (good) | Signal predicted to be reliably available at this location | Useful starting point but theoretical |
| Amber coverage area (variable) | Signal may be available but inconsistently | Indicates potential problems worth investigating |
| Red / no colour (none) | Signal not predicted to be available | Strongly suggests that network will not work here |
| Performance dial -- high % | Most crowdsourced measurements in your district achieved good performance | Most useful indicator of real-world experience |
| Performance dial -- low % | Many users in your area cannot achieve good performance on this network | Consider switching if consistently low |
Understanding coverage versus performance -- why they differ
A common experience is seeing good coverage on the map but still experiencing poor connection quality in practice. This is not an error in the tool -- it reflects a genuine difference between two separate aspects of mobile connectivity that Ofcom explicitly distinguishes in its June 2026 consultation.
Coverage is the availability of signal. If signal is available, your phone can connect to the network. Performance is whether the network has enough capacity to serve your connection with adequate speed and responsiveness. In a congested area -- a busy city centre at lunchtime, a shopping centre on a Saturday, a train station during rush hour -- many users simultaneously compete for the same network resources. Even where coverage is good, capacity constraints mean each user receives reduced speed and increased latency. Coverage is present; performance is not.
This is why Ofcom updated Map Your Mobile to include performance data alongside coverage maps. The performance data, derived from crowdsourced measurements across your postcode district, captures the real-world experience of users in your area at various times of day and conditions -- not just the theoretical signal availability.
Which networks are covered and what about MVNOs
Map Your Mobile covers the four major mobile network operators (MNOs) that own and operate UK mobile infrastructure: EE, O2, Three and Vodafone. Virtual operators (MVNOs) that do not own their own networks are not shown separately because they use one of these four underlying networks.
| Host network | MVNOs using this network (examples) |
|---|---|
| EE | BT Mobile, Plusnet Mobile, 1pMobile, Utility Warehouse, Ecotalk, Your Co-op |
| O2 | Tesco Mobile, giffgaff, Sky Mobile, Lycamobile |
| Three | SMARTY, iD Mobile, Superdrug Mobile |
| Vodafone | VOXI, Lebara Mobile, Asda Mobile, talkmobile |
If you are on an MVNO, check which host network they use and look up that network's coverage in Map Your Mobile. MVNO customers use the same physical network infrastructure as the host network's direct customers. In areas of poor coverage on the host network, MVNO customers will experience the same poor coverage.
Note that VodafoneThree, the merged entity formed by the Vodafone and Three merger in 2024, operates both the Vodafone and Three networks. MOCN (Multi-Operator Core Network) sharing means customers of both networks can access the combined infrastructure, which has improved coverage and performance across 16,500 square kilometres of the UK.
What to do if your coverage or performance is poor
Enable Wi-Fi calling
Wi-Fi calling allows your phone to make and receive normal voice calls and texts over a Wi-Fi connection rather than the mobile network. If mobile signal is weak -- indoors, underground, in areas with poor coverage -- Wi-Fi calling routes your call through your broadband connection instead. It uses your normal phone number, requires no separate app, and is supported by all four major UK networks. Check that Wi-Fi calling is enabled in your phone settings and that your network has it active on your account.
Compare alternative networks
Use Map Your Mobile to compare performance scores across all four networks at your postcode. If your current network has a significantly lower performance score than alternatives, switching may meaningfully improve your experience. Use Ofcom's switching guides -- text 'PAC' to 65075 for mobile number porting -- to move to a better-performing network without losing your number.
Check signal at different times
Performance varies with demand. A network that performs well at 6am may be congested at noon in a busy urban area. If you experience poor performance at specific times (rush hour, lunchtime, weekends in busy areas), congestion rather than coverage is likely the cause. Map Your Mobile's performance data averages across all times and conditions -- checking at different periods on the actual network will give you a more granular view.
Report persistent coverage gaps
If you consistently have no mobile signal in an area where you would expect coverage -- a residential area, a major road, a town centre -- you can report this to Ofcom at ofcom.org.uk. Ofcom uses consumer reports to monitor network compliance with coverage obligations including the Shared Rural Network commitments and to identify areas for regulatory attention.
How Map Your Mobile data is collected and updated
Coverage data is submitted periodically to Ofcom by the mobile network operators. It is based on theoretical signal propagation modelling using each network's antenna configuration, power levels, and UK terrain and building data. Ofcom updates the coverage maps as networks provide new data following infrastructure changes, new mast deployments and technology upgrades.
Performance data is collected continuously through Opensignal's crowdsourcing methodology. Millions of measurements are made each month by devices running the Opensignal app or using services that contribute anonymised performance data. The performance scores shown in Map Your Mobile reflect a rolling window of this crowdsourced data, weighted to represent typical user experience in each postcode district.
Because performance data requires a sufficient volume of measurements to be statistically reliable, coverage at a very granular level (a small hamlet, a remote location) may not have performance data if too few crowdsourced measurements have been made there. In these cases, Ofcom scales to the wider postcode area.
Map Your Mobile and Ofcom's broader connectivity programme
Map Your Mobile reached one million visits by May 2026 -- a significant uptake for a tool that was substantially updated and relaunched with performance data in 2025. Price comparison websites GoCompare and Which? have incorporated the underlying crowdsourced performance data into their own mobile comparison tools, extending the reach of Ofcom's data to consumers who may not directly use the Ofcom tool.
Ofcom has stated it will continue to develop Map Your Mobile as part of its 'Connectivity You Can Count On' work programme. Planned developments include more granular coverage data, updated performance benchmarks as the 90% target framework is developed, and potentially more specific reporting on connectivity in problem locations such as train routes.
Related guides
Disclaimer: This guide is for informational purposes only. Kael Tripton Ltd is not regulated by the FCA and does not provide financial or telecoms advice. Data sourced from Ofcom, the UK communications regulator. Always verify current information at ofcom.org.uk.
Frequently asked questions
How do I check mobile coverage in my area?
Use Ofcom's free Map Your Mobile tool at checker.ofcom.org.uk. Enter your postcode to see coverage and performance data for EE, O2, Three and Vodafone simultaneously. No registration required. The tool shows both theoretical coverage (operator-modelled signal predictions) and real-world performance scores based on crowdsourced measurements from actual users.
What is the difference between coverage and performance on Map Your Mobile?
Coverage shows whether signal is theoretically predicted to be available at your location, based on operator signal propagation models. Performance shows the percentage of real crowdsourced measurements in your postcode district that achieved good performance (5+ Mbit/s download, 1.5+ Mbit/s upload, 50ms or less latency). Coverage can be good while performance is poor if the network is congested. Performance data is more useful for assessing real-world experience.
Why does my phone show signal but data is slow?
Signal bars show connection strength, not network performance. You can have a strong signal to a congested mast and still experience slow data because many users are sharing the same network resources simultaneously. This is common in busy urban areas, train stations, shopping centres and during peak hours. Checking the performance score on Map Your Mobile will show whether this is a known pattern in your area.
Which mobile network has the best coverage in the UK?
EE consistently leads in overall 4G network coverage and 5G reach according to Ofcom's Connected Nations data. However, the best network depends on your specific location. Use Map Your Mobile to compare all four networks at your postcode rather than relying on headline statistics. Ofcom's crowdsourced performance data within the tool is more useful than coverage maps alone for predicting real-world experience.
Does Map Your Mobile show MVNO coverage?
Map Your Mobile shows the four major network operators -- EE, O2, Three and Vodafone. MVNOs are not shown separately because they use one of these four underlying networks. If you are on an MVNO, look up which host network they use: giffgaff, Sky Mobile and Tesco Mobile use O2; SMARTY and iD Mobile use Three; VOXI and Asda Mobile use Vodafone; BT Mobile and Plusnet use EE.
How often is Map Your Mobile updated?
Coverage data is updated periodically as mobile network operators submit new network data to Ofcom following infrastructure changes and upgrades. Performance data from crowdsourced measurements is updated on a rolling basis. Ofcom does not publish a specific update schedule -- check the tool for the most current data.
What should I do if Map Your Mobile shows no coverage at my address?
If you have no coverage at your address on your current network, check alternative networks using Map Your Mobile. If all four networks show no coverage or variable coverage, report the gap to Ofcom at ofcom.org.uk. You can also check if your broadband provider supports Wi-Fi calling, which routes calls over your broadband connection instead of mobile signal. For consistent coverage problems in residential areas, Ofcom's Shared Rural Network programme may eventually address the gap.
Is Map Your Mobile the most accurate mobile coverage checker?
Map Your Mobile is the most authoritative independent checker for UK consumers because it is published by Ofcom, the regulator, using independently verified data. Individual network coverage maps use the same operators' own modelling data but without independent verification. Map Your Mobile adds real-world crowdsourced performance data that individual network maps do not provide. For the most accurate reading of coverage at a specific location, checking Map Your Mobile alongside your network's own tool and testing signal in person gives the fullest picture.
