Ofcom Mobile Coverage Checker – UK 4G & 5G Coverage Guide

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In 2025, having reliable mobile signal isn’t just a convenience, it’s often essential. Whether you’re working remotely, streaming media, navigating with GPS, or staying in touch with friends and family, consistent 4G or 5G connectivity can make or break your day. But coverage isn’t uniform: it can vary street by street, between indoors and outdoors, and shift over time due to new masts or changes in the environment.

That’s why a tool that helps you check real-world network performance at your exact postcode can be invaluable.

What is the Ofcom mobile coverage checker

The Ofcom mobile coverage checker (now rebranded as Map Your Mobile) is an online tool provided by the UK’s telecom regulator. It lets UK residents enter a postcode (or address) and see which major networks provide 4G or 5G signal in that area.

For each network, the checker gives two complementary types of information:

• Coverage map: A detailed map (down to 50×50 m grid cells) showing whether 4G/5G signal is likely to be available outdoors, indoors (or both), whether the signal is likely to be good or variable.

• Performance estimate: A “performance” indicator that estimates how likely your connection is to support more data-heavy uses (for example, streaming video) based on recent real-world usage data.

This makes the checker more than just a “bars on a map”: it’s designed to reflect modern mobile usage (streaming, data, calls) and help users choose networks accordingly.

The tool includes coverage info for the UK’s four main mobile networks; other providers usually piggyback off one of those core networks.

How the coverage data is generated — and what its limits are

To produce its maps, Ofcom relies on a combination of:

• Predictive data from mobile network operators (MNOs), calculating signal strength across every 50 m × 50 m square of UK land using modelling that takes into account antenna power, geography, and obstacles.

• Crowdsourced real-world measurements — for performance data (e.g. people’s ability to stream video or make video calls in that area).

Because of this hybrid approach, the checker paints a fairly good picture of likely network quality — but it cannot guarantee that the coverage you see on the map matches exactly what you’ll get. Local factors can affect signal strength:

• Obstacles such as hills, dense trees, or buildings can block or weaken signal.

• Indoor reception depends heavily on building materials and layout (walls, windows, insulation).

• Mast capacity and network congestion, especially at busy times, can impact performance.

• The model’s predictions are based on averages — so one street or even one building may differ from the “map average.”

Ofcom itself notes that the information is “a guide” rather than a guarantee.

Practical tips for using the checker

1. Check before you move — If you’re thinking of renting or buying a new home (even just checking for interested friends), run your postcode through the checker. You might discover that one network performs much better than others in that area.

2. Use it for travel or commuting planning — For example, if you regularly drive or travel somewhere with patchy coverage, the checker can highlight where mobile signal is likely to drop, helping you plan or pick the best network.

3. Check both outdoor and indoor coverage — Look at the “good outdoor & in-home” vs “outdoor only / variable in-home” zones. If your home is old, or has thick walls, indoor coverage might be worse, plan accordingly.

4. If coverage is poor, check alternatives — Some providers support Wi-Fi calling, or you may consider mobile signal repeaters for your home. Ofcom points this out for folks with patchy indoor reception.

5. Use it as a guide — Because real-world factors (terrain, building materials, congestion) vary, it’s worth trying your phone near windows/outside, or at different times of day. The checker gives a baseline, but your own experience may differ.

A simple tool — but potentially a lifesaver

The Ofcom mobile coverage checker won’t solve every dead zone or guarantee perfect signal. But by combining predictive and crowdsourced data, and offering an easy way to compare all major UK networks by postcode, it gives people real buying power when choosing a network, a home, or a commute.

In a world where being connected is increasingly essential (whether for work, study, or staying close to loved ones) tools like Map Your Mobile offer clarity and control.