This guide answers one question for Bristol: which mobile network gives the best signal, and where the answer changes. Every figure in it is Ofcom's own measurement: the Ofcom Mobile Coverage data (May 2025) behind NetScan's Bristol coverage checker, covering 1,478 addresses in 85 sampled postcodes across 16 postcode districts (BS1 to BS20). Nothing here is estimated, and no network is called best where the data does not say so.
Across Bristol as a whole, no network wins on coverage: Ofcom's overall scores are O2 100, Vodafone 100, Three 98, EE 97 out of 100, a spread of 3 points, which is too close to call a winner. Outdoors they are level: all four reach good outdoor 4G and Ofcom's top 'enhanced' outdoor grade at 100% of the addresses sampled. Indoors they are not: good indoor signal ranges from 83% of addresses (EE) to 100% (O2).
The real differences are local. In 6 of the 16 districts, at least one network's indoor figure sits 5 or more points behind the others, and the gap can be large: in BS20, Ofcom finds good indoor EE signal at 4% of the 191 addresses it sampled. This guide maps those districts, so you can see whether yours is one of them before you pick a network.
Bristol at a glance: the four networks on Ofcom's figures
These are the Bristol-wide figures, pooled across all 16 districts and weighted by the number of addresses sampled in each. They are the same numbers the Bristol coverage checker shows. The order is the checker's (overall score, ties broken alphabetically); it is not a recommendation.
What the columns mean: Ofcom grades the predicted signal at each address. '5G-grade outdoor' is the share of addresses at Ofcom's top 'enhanced' outdoor data grade, a signal-strength grade rather than a promise of 5G service on your plan. 'Good outdoor 4G' is the share with good or better outdoor data signal, and 'Good indoor' the share with good or better indoor data signal. 'Overall' blends the three (35%, 50% and 15%).
| Network | Overall | 5G-grade outdoor | Good outdoor 4G | Good indoor |
|---|---|---|---|---|
| O2 | 100/100 | 100% | 100% | 100% |
| Vodafone | 100/100 | 100% | 100% | 100% |
| Three | 98/100 | 100% | 100% | 90% |
| EE | 97/100 | 100% | 100% | 83% |
Source: Ofcom Mobile Coverage data (May 2025), 1,478 addresses in 85 postcodes, BS1 to BS20.
Where the networks differ in Bristol: district by district
The Bristol-wide averages hide the districts where one network falls behind indoors. The table lists every district where the four networks' good-indoor figures are 5 or more points apart. The lowest readings are EE in BS20 (4% of 191 addresses), Three in BS20 (26% of 191 addresses), EE in BS4 (67% of 106 addresses) and EE in BS7 (70% of 69 addresses).
It is not the same network everywhere. Trailing by 5 or more points indoors: EE in BS4, BS7, BS10, BS13 and BS20; Three in BS11 and BS20. That is why a single 'best network in Bristol' answer does not hold up, and why the district you live or work in matters more than the city.
In every one of these districts all four networks are level outdoors; the difference is indoor signal only.
| District | Addresses | EE | O2 | Three | Vodafone |
|---|---|---|---|---|---|
| BS4 | 106 | 67% | 100% | 100% | 100% |
| BS7 | 69 | 70% | 100% | 100% | 100% |
| BS10 | 75 | 93% | 100% | 100% | 100% |
| BS11 | 83 | 100% | 100% | 84% | 100% |
| BS13 | 57 | 93% | 100% | 100% | 100% |
| BS20 | 191 | 4% | 100% | 26% | 100% |
Good indoor data signal, share of sampled addresses. Ofcom Mobile Coverage data (May 2025).
The Bristol districts where all four measure the same
In 10 of the 16 districts (BS1, BS2, BS3, BS5, BS6, BS8, BS9, BS14, BS15 and BS16) Ofcom's figures are identical for EE, O2, Three and Vodafone on all three measures: 5G-grade outdoor, good outdoor 4G and good indoor. If your address is in one of these, the coverage data gives you no reason to prefer one network, so the useful comparison is plan price, contract length and roaming, including the cheaper SIM brands that share each network's masts.
Choosing a network in Bristol with this data
Start with your district rather than the city. If it is in the table above, look at which network trails there and treat that as the one to check hardest, especially if you use your phone mostly indoors. A figure like 4% means most sampled addresses in BS20 are not predicted good indoor EE signal; it does not mean yours is one of them, so check your own postcode.
If your district is not in the table, the four networks measure within 5 points of each other indoors there and are level outdoors, so the decision moves to price and terms. Either way, the network you choose also decides which SIM brands you can use on it: giffgaff and Tesco Mobile run on O2's masts; SMARTY and iD Mobile on Three's; VOXI, Talkmobile and Lebara on Vodafone's; and 1pMobile on EE's. A SIM brand gets its host network's coverage, so the district figures above apply to it as well. Plan prices change often, so check the provider's own site for today's price.
What Ofcom's figures can and can't tell you
Ofcom's data is a prediction of signal at each sampled address, not a speed test, and the sample per district ranges from 19 to 191 addresses in Bristol. Indoor signal in particular depends on the building: thick walls, basements and foil-backed insulation all cut it. The figures cover the 16 districts from BS1 to BS20 that NetScan holds Ofcom measurements for.
Two practical checks close the gap. Run your full postcode through NetScan's scanner to see the four networks for your own district, then confirm on the operator's own coverage checker. If indoor signal is the problem at home, Wi-Fi calling on a compatible phone and plan routes calls over your broadband instead.