Comparing EE, Vodafone, O2 and Three across 5G · 4G · 3G for the Chelmsford (CM) postcode area. Use the scanner below to check your exact postcode.
Ofcom measures EE, O2, Three and Vodafone within 3 points in Chelmsford (CM), so no network wins here on coverage. Pick on price — then check your own postcode, because indoor signal still varies street by street.
No network wins Chelmsford on coverage. All four are within 3 points of each other in Ofcom's measurements, across 1,206 addresses sampled in 51 postcodes. On a difference that small, EE, O2, Three and Vodafone will all work here — so choose on price, contract length and roaming, not on a coverage map. Coverage only becomes the deciding factor once you leave built-up areas, and it still varies street by street indoors: check your own postcode below to see the measurement for your address rather than for Chelmsford as a whole.
Ranked by Ofcom's overall score: EE 100, O2 100, Vodafone 99, Three 97. The spread between best and worst is 3 points, which is inside the margin where a coverage figure stops being a useful tiebreak. Ofcom's data describes outdoor signal across sampled addresses; it cannot tell you how any of them behave inside your own building.
These scores for Chelmsford are Ofcom's own measurements, taken from the Ofcom Mobile Coverage API (May 2025 data) across 1,206 addresses in 51 postcodes. They describe outdoor signal at sampled addresses across the whole of Chelmsford; signal inside a specific building, and on a specific street, can differ from the area figure.
Every network clears the bar in the CM postcode area, so the honest advice is to stop comparing coverage maps and start comparing prices — the difference between the cheapest and dearest plan will dwarf a 3-point coverage gap. Check your own postcode above first: indoor signal varies street by street even where the area figures match.
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No network wins Chelmsford on coverage. Ofcom's measurements rate EE, O2, Three and Vodafone within 3 points of each other here (EE 100, O2 100, Vodafone 99, Three 97 out of 100), which is too close to call a winner. All four will work in Chelmsford, so choose on price, contract length and roaming instead.
EE reaches enhanced (5G-grade) outdoor signal at 100% of the addresses Ofcom sampled in Chelmsford, and the other three are within 3 points of it.
O2 is the second-best operator in Chelmsford with 100/100 overall (100% 5G, 100% 4G).
Chelmsford is classified as a mixed urban-rural area with a population density score of 64%. Mixed areas typically see good 4G and growing 5G from leading operators.
Check mobile coverage for specific postcode districts in Chelmsford:
Compare mobile coverage in nearby East of England areas:
