| Network | Which? score | Ofcom complaints* | Uses | eSIM | Wi-Fi calling | Rollover | Phone support | From |
|---|---|---|---|---|---|---|---|---|
| Talkmobile | 83% |
Not listed | Vodafone | Yes | Yes | No | Yes | £4.98/mo |
| Tesco Mobile | 81% |
2 | O2 | Yes | Yes | No | Yes | £6/mo |
| giffgaff | 79% |
1 | O2 | Yes | Yes | No | No | £6/mo |
| SMARTY | 79% |
Not listed | Three | Yes | Yes | No | No | £6/mo |
| VOXI | 79% |
Not listed | Vodafone | Yes | Yes | – | No | £10/mo |
| Lebara | 78% |
Not listed | Vodafone | Yes | Yes | No | Yes | £1.48/mo |
| 1pMobile | 78% |
Not listed | EE | Yes | Yes | – | Yes | £4/mo |
| Asda Mobile | 77% |
Not listed | Vodafone | Yes | Yes | Yes | Yes | £5/mo |
| EE | 74% |
1 | EE | Yes | Yes | Yes | Yes | £9/mo |
| iD Mobile | 73% |
3 | Three | Yes | Yes | Yes | No | £5/mo |
| Sky Mobile | 73% |
4 | O2 | Yes | Yes | Yes | Yes | £4/mo |
| Vodafone | 72% |
1 | Vodafone | Yes | Yes | Yes | Yes | £7/mo |
| Lyca Mobile | 68% |
Not listed | EE | Yes | Yes | No | Yes | £3.50/mo |
| O2 | 67% |
3 | O2 | Yes | Yes | Yes | Yes | £7/mo |
| Three | 65% |
2 | Three | Yes | Yes | – | Yes | £7/mo |
| spusu | – | Not listed | EE | Yes | Yes | – | Yes | £3.90/mo |
Which? scores from its January 2026 survey of 5,137 UK mobile customers. *Ofcom pay-monthly complaints per 100,000 customers, January to March 2026 (industry average 2, lower is better). Smaller networks aren't listed by Ofcom. "From" is the lowest monthly price, including intro offers.
Talkmobile
Talkmobile is Vodafone's low-cost SIM brand and came top of the 2026 Which? survey. Simple, cheap plans with phone support and no price rises, but few extras.
Tesco Mobile
Tesco Mobile runs on O2 and is known for top customer service, Clubcard discounts and uncapped roaming in 48 destinations. A strong all-rounder, especially for Clubcard holders.
giffgaff
giffgaff is an O2-owned, online-only network with no credit checks and a busy community help forum. Good for people happy to sort things out online, but there is no phone support.
SMARTY
SMARTY is Three's no-frills, 30-day SIM brand with no credit check and no annual price rises. Support is online only, but it scores well with customers.
VOXI
VOXI is Vodafone's 30-day SIM brand built around endless social media, music and video data. Great value for heavy app users, but support is chat and social only and roaming costs extra.
Lebara
Lebara is a Vodafone-based network aimed at people who call abroad, with free international minutes and strong EU roaming. No credit check, no price rises and long support hours make it an easy pick.
1pMobile
1pMobile is a small EE-based network owned by Telecom Plus, famous for 1p per minute, text and MB pay as you go. Ideal for light users and backup phones, with UK phone support in office hours.
Asda Mobile
Asda Mobile is Asda's budget SIM brand on the Vodafone network, with data rollover on pay monthly and Asda Rewards tie-ins. A solid cheap option with free phone support.
EE
EE is owned by BT and consistently wins independent tests for speed and reliability, with low complaints. You pay a premium for it and roaming costs extra.
iD Mobile
iD Mobile is Currys' network on Three, with data rollover, bill capping and roaming in 50 destinations. Good value on features, but support is chat-based and pay monthly plans need a credit check.
Sky Mobile
Sky Mobile runs on O2 and stands out for Piggybank, which saves your unused data, plus £2-a-day roaming in 120 destinations. It had the highest Ofcom complaint rate in Q1 2026, mostly about switching.
Vodafone
Vodafone is one of the big four networks, now part of VodafoneThree and sharing masts with Three. Complaints are low, but roaming costs extra and prices rise each April.
Lyca Mobile
Lyca Mobile is a budget, international-calling focused network running on EE. Cheap and flexible, but it has lagged on features and scores below average with Which? customers.
O2
O2 is one of the big four networks, with free EU roaming up to 25GB, Priority rewards and strong coverage. It scores poorly with customers in the Which? survey and prices rise every April.
Three
Three is one of the big four networks, strong on 5G speeds and perks through Three+, and now part of VodafoneThree. It came bottom of the 2026 Which? satisfaction survey and roaming is no longer free.
spusu
spusu is an Austrian network that launched in the UK in June 2023, running on EE with rolling monthly plans. Cheap, no credit check and genuine phone support, but still little known here.