This guide answers one question for Preston: 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 Preston coverage checker, covering 1,147 addresses in 52 sampled postcodes across 9 postcode districts (PR1 to PR9). Nothing here is estimated, and no network is called best where the data does not say so.
Across Preston as a whole, no network wins on coverage: Ofcom's overall scores are O2 100, Vodafone 100, EE 98, Three 98 out of 100, a spread of 2 points, which is too close to call a winner. Outdoors they are level: across the four, good outdoor 4G reaches 100% of sampled addresses and Ofcom's top 'enhanced' outdoor grade 99-100%. Indoors they are not: good indoor signal ranges from 84% of addresses (Three) to 100% (O2).
The real differences are local. In 5 of the 9 districts, at least one network's indoor figure sits 5 or more points behind the others, and the gap can be large: in PR8, Ofcom finds good indoor Three signal at 32% of the 150 addresses it sampled. This guide maps those districts, so you can see whether yours is one of them before you pick a network.
Preston at a glance: the four networks on Ofcom's figures
These are the Preston-wide figures, pooled across all 9 districts and weighted by the number of addresses sampled in each. They are the same numbers the Preston 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% | 98% |
| EE | 98/100 | 99% | 100% | 92% |
| Three | 98/100 | 100% | 100% | 84% |
Source: Ofcom Mobile Coverage data (May 2025), 1,147 addresses in 52 postcodes, PR1 to PR9.
Where the networks differ in Preston: district by district
The Preston-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 Three in PR8 (32% of 150 addresses), Three in PR3 (42% of 55 addresses), EE in PR9 (55% of 113 addresses) and Three in PR9 (79% of 113 addresses).
It is not the same network everywhere. Trailing by 5 or more points indoors: EE in PR3, PR4, PR7 and PR9; Three in PR3, PR4, PR8 and PR9; Vodafone in PR4. That is why a single 'best network in Preston' 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 |
|---|---|---|---|---|---|
| PR3 | 55 | 95% | 100% | 42% | 100% |
| PR4 | 122 | 89% | 96% | 83% | 80% |
| PR7 | 219 | 90% | 100% | 100% | 100% |
| PR8 | 150 | 99% | 100% | 32% | 100% |
| PR9 | 113 | 55% | 100% | 79% | 100% |
Good indoor data signal, share of sampled addresses. Ofcom Mobile Coverage data (May 2025).
The Preston districts where all four measure the same
In 4 of the 9 districts (PR1, PR2, PR5 and PR6) 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 Preston 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 32% means most sampled addresses in PR8 are not predicted good indoor Three 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 55 to 219 addresses in Preston. Indoor signal in particular depends on the building: thick walls, basements and foil-backed insulation all cut it. The figures cover the 9 districts from PR1 to PR9 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.