The UK's Cheapest SIM-Only Phone Deals From BT Mobile, O2, EE, Three and More (Updated)

By Gerald Lynch on at

EE partnering with BT to form BT Mobile; Three UK teaming up with O2 to make a mobile network supergroup -- it's been a busy day already for the UK mobile industry, and a potentially confusing one for those considering a new mobile contract.

If you're after the most affordable deals, SIM-only plans are certainly the way forward, letting you pick up any phone you like outside of the contract, keeping monthly costs to a minimum. With BT flirting with mobiles once again, the race to the bottom for SIM-only pricing is heating up, so this guide should help you pick from the cheapest SIM-only plans one suitable for your needs.

A few things to note before I get started though. I'm looking at the best of the cheapest deals, not necessarily the best overall. Inspired by today's super-low-cost SIM-only announcement from the newly formed BT Mobile, I thought it'd be handy to put the value-orientated plans up against each other.

As such, the allowances are very modest indeed -- for just a few quid more you can get far greater data deals, and more minutes too. They're probably not suitable for heavy smartphone users then, though could suit a child's first phone, a personal second phone (drug dealers and cheaters unite!), or maybe an investment just to take advantage of a network's unique perks. Also, I've ignored Pay As You Go and rolling monthly deals -- while they tend to be more flexible, that flexibility generally comes at a higher cost, which is counter to this "cheapest" deal hunt.

So, if rock-bottom pricing is simply what you're after, these SIM-only plans should be your first consideration.

BT Mobile

New kid on the block BT came charging out of the stalls today with its new BT Mobile network and some headline-grabbing SIM-only deals to boot. For £5 a month it offers 500MB of 4G data, unlimited texts and 200 minutes. It's a basic offering lasting 12 months using EE's mobile infrastructure, and you'd want to put a bill-cap on that 500MB of data as you'll fly through it in a single sitting. But if it's just a phone deal needed to keep track of a youngster, it might do the trick.

However, that £5 pricing is only offered if you're also one of BT's Broadband subscribers. Otherwise, expect to pay £10 a month. Check out BT Mobile's deals here.

Three UK

Three UK's cheapest SIM-only plan starts a little higher than BT's at £8 a month, but also arguably has better perks. It's another 12-month contract, giving you 500MB of 4G data, 200 minutes and unlimited texts and calls to 0800/0500 numbers. However, you also gain access to Three's superb "Feel at Home" roaming service, letting you use your phone just as you would in the UK in 16 international destinations (soon to rise to 18) without returning to a shockingly high bill. Three also lets you use your phone as a personal Wi-Fi hotspot. Take a look at Three UK's SIM-only deals here.


You're looking at a starting price of £9.99 for EE's SIM-only plans, which trade on higher talk-time minutes than data allowances. For that tenner a month over a 12 month period, you get a measly 250MB of 4G data, 250 minutes and unlimited texts. Good if you're a bit chattier, not so good if you're on the internet lots. You do however get to benefit from the EE Film Club, letting you get a £1 movie download once a week, as well as the fastest 4G network and the most consistent 4G coverage of any provider. Check out the EE SIM-only deals here.


You're going to struggle to get a decent ultra-budget deal of any value from O2. With 12 month plans starting at £8.00 a month, you don't even get 4G data access, leaving you resigned to O2's 3G offering. That eight quid gets you 100 minutes, 100MB of data and unlimited texts. O2's perks are good though, ranging from priority gig tickets to VIP lounge access at venues, as well as deals on Evernote premium subscriptions. Have a look at O2's SIM-only deals here.


If you're after call time, Vodafone has a decent offering. It's 300 Plan costs £9.50 a month on a 12 month deal, and gives you 300 UK minutes, 500 texts and 250MB of data. You're limited to 3G data though, and can't access Vodafone's Now TV, Spotify or Sky Sports perks. But if you just like a good natter on the cheap, it's worth a look. Check out Vodafone's SIM-only plans here.

Tesco Mobile

Of all the MVNOs, Tesco Mobile's SIM-only plans shouldn't be sniffed at when it comes to value. For £7.50 a month on a 12 month plan, you get 250 minutes, 5,000 texts and 500MB of data. I'd argue that Three's slightly more expensive deal is better value thanks to its 4G offering, but with Tesco Mobile letting you tot up extra Clubcard points alongside its mobile deals, it'll appeal to the supermarket's most-loyal customers. Check out Tesco Mobile's SIM-only plans here.


TalkTalk has slashed its SIM-only prices by half for the first 12 months, so if you're looking for a temporary contract, it's absolutely worth checking out what it's offering. For £3.75 a month (usually £7.50) you get get 250MB, 300 minutes and 250 texts. Check out TalkTalk's plans here.


GiffGaff is the wildcard here, but if you're ready for a bit of a gamble and prize talk time above all else, its £5 a month Hokey Cokey deal is worth considering. At its base level, it's very basic, giving you 60 UK minutes, 300 UK texts and 20MB of data. So this is in no way a plan suitable for smartphone users. However, for every minute that someone calls you, GiffGaff will give you back an extra call time minute back for free. Bessie mates that talk into the early hours could benefit here. Check out the kooky offer from GiffGaff here.

Carphone Warehouse iD

Phone retailer Carphone Warehouse has announced that it too is set to establish itself as an MVNO. While it's SIM-only contract deals have yet to be shared, it's stated that a selection of 12 and 24 month contracts will be available, as well as free roaming in 22 countries. We'll keep you posted on whether or not its eventual deals are worth your while.

Verdict and Winning Plan: Three

It's a close run race, especially for BT Broadband customers, but for me Three's entry-level SIM-only deal is the most compelling. It's reasonably priced and is among the most generous with its allowances. But best of all is the Feel at Home service -- an absolute life-saver when travelling abroad.

Image Credit: Close-up very small Nano SIM / mixed UK money (modified) from Shutterstock

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