Ongar mobile coverage Three 80% indoors here, 100% in CM4 nearby CM5 · Brentwood
No network wins CM5 on overall coverage: all four are within 3 points, but indoors EE reaches 100% of sampled addresses and Three 80%.
CM5: Ongar, Fyfield, Moreton, Roxwell, High Laver, High Ongar, Willingale, Bobbingworth (Brentwood, Chelmsford, Epping Forest).
CM5 scores
Ofcom Mobile Coverage data (May 2025), measured across 188 addresses in 6 sampled postcodes: CM5 0AA, CM5 0AX, CM5 0BW, CM5 0FW, CM5 0TH, CM5 9BL. Methodology.
How CM5 compares
Every network here is within 8 points of the Chelmsford average, indoors and outdoors.
Weakest spot in Chelmsford: CM9 Maldon, where Three reaches 50% indoors.
Indoor signal around CM5
| District | km away | EE | O2 | Three | Vodafone |
|---|---|---|---|---|---|
| CM5 Ongar (here) | – | 100% | 96% | 80% | 96% |
| CM4 Billericay, Margaretting | 11 | 100% | 100% | 100% | 100% |
| CM1 Writtle, Broomfield | 15 | 100% | 100% | 100% | 100% |
| CM2 Great Baddow, Sandon | 16 | 100% | 100% | 100% | 100% |
| CM6 Great Dunmow, Felsted | 19 | 95% | 100% | 57% | 97% |
| Chelmsford average | – | 97% | 98% | 83% | 93% |
Biggest difference nearby: Three indoors, 80% here and 100% in CM4 Billericay, 11 km away.
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1pMobile runs on EE's network: £5 a month for 5GB (read 19 October 2026). A price, not a coverage ranking: Ofcom separates no network here.
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