Q1
Best network for CO9?
Three leads with 98/100 — driven by 100% 5G and 100% 4G in this mixed urban-rural part of Colchester.
CO9 DISTRICT · BRAINTREE
Best mobile network in Stour Valley CO9 · Braintree
Three scores 98/100 — the best measured network for CO9 in Colchester, 6 points clear of the weakest. 100% 5G-grade · 100% 4G. Ofcom Mobile Coverage data (May 2025), measured across 70 addresses in 5 sampled postcodes.
The CO9 district covers Stour Valley, Gosfield, Coggeshall and Greenstead Green, in Braintree. Signal varies street by street — scan your exact postcode below.
RESULT · CO9 · COLCHESTER
Coverage for CO9 district
★ BEST MEASURED
Three
98/100
Three has the strongest measured coverage for the CO9 district in Colchester, 6 points clear of the weakest network in Ofcom's data.
Full ranking — CO9
#1
Three
#2
EE
#3
O2
#4
Vodafone
Coverage analysis — CO9
Drawing on Ofcom's sampled address-level coverage, Three leads the field in Colchester. In this mixed urban-rural area, Three achieves an overall coverage score of 98/100 — driven by excellent 5G coverage (100%) and rock-solid 4G at 100%. 5G and 4G scores are closely matched, reflecting a mature, stable network.
Three clearly leads EE by 2 points overall. While EE reaches 93% on 5G and 100% on 4G in Colchester, it falls short of Three's combined performance across all bands. O2 and Vodafone round out the field at 92 and 92 respectively.
Why Three for CO9?
Three's 5G rollout in Colchester is among the strongest nationally, covering 100% of premises in the CO9 district. For anyone streaming video, gaming on mobile, or relying on a mobile hotspot at home, this level of 5G penetration makes a real difference to day-to-day speed.
The runner-up in CO9 is EE at 96/100 (93% 5G / 100% 4G). It is a close contest — both operators deliver strong coverage in CO9, and your choice may come down to tariff, handset preference, or existing contract.
Switching to Three in Stour Valley
Three has the strongest measured signal here — 98/100, with 100% 5G-grade and 100% 4G coverage across Stour Valley, Gosfield, Coggeshall and Greenstead Green, 6 points clear of the weakest. A cheaper plan on a network that does not reach your street costs more than it saves, so start from the coverage and pick the plan second.
Some links on this page are affiliate links. If you switch through one we may be paid a commission. It never changes which network we rank first - that comes from Ofcom coverage data alone.
Explore the Colchester area
View full coverage analysis for the Colchester (CO) area, or enter any UK postcode in the scanner above for a personalised result.
Coverage FAQ — CO9
Q2
Is 5G available in CO9?
Three provides excellent 5G coverage at 100%. EE follows at 93%.
Q3
Which network has the best 4G?
Three leads 4G too at 100%. Reliable 4G is critical in mixed urban-rural areas.
Q4
Is O2 worth considering?
O2 scores 92/100 in CO9 (93% 5G, 100% 4G). It may suit certain tariff or price preferences despite trailing the top two.