Your phone has two SIM slots for a reason, but British networks have spent years pretending this feature doesn’t exist. While they push £69 monthly contracts that lock you in for two years, thousands of UK families have discovered the dual-SIM setup that cuts phone bills by 70% without sacrificing anything.
The maths is embarrassingly simple once you see it. Yet walk into any EE, O2, or Vodafone shop and ask about running dual-SIM with an eSIM for data, and watch the staff suddenly develop amnesia about how phones work.
The £380 Yearly Saving Most Families Miss
Here’s what a typical UK family spends on mobile phones: four contracts at £30-40 each, totaling £120-160 monthly. That’s £1,440-1,920 yearly for unlimited calls and 20-30GB data per person. The kids barely make phone calls, the parents use maybe 500 minutes monthly, yet everyone’s paying for unlimited everything.
The dual-SIM method flips this completely. You keep your existing phone number on a basic PAYG SIM – Asda Mobile does 100 minutes and unlimited texts for £5 monthly. Your actual data comes through an eSIM UK provider on the phone’s second slot. Data-only eSIMs cost a fraction of traditional plans because they don’t include the voice infrastructure networks maintain.
Take the Robinson family from Leeds. Four phones, previously paying £35 each with Three for unlimited calls and 30GB data. Monthly bill: £140. They switched to Tesco Mobile PAYG SIMs (£7.50 each for basic calls/texts) plus data-only eSIMs at £12 for 30GB. New monthly cost: £78. Annual saving: £744.
The setup takes 20 minutes per phone. You port your number to the PAYG provider (keeps your WhatsApp active), then add the eSIM for data. Both stay active simultaneously – calls route through the physical SIM, data through the eSIM. No juggling, no switching, no complications.
Why Networks Bury eSIM Options
Physical SIM cards create friction. Lost your SIM? Wait three days for postal delivery. Want to switch networks? Visit a shop or wait for post. Phone locked to a network? You’re stuck until the contract ends.
eSIMs destroy these barriers. Switching takes five minutes from your sofa. No store visits, no waiting, no locked phones. Networks know this threatens their entire business model built on customer inertia.
EE technically offers eSIM but requires visiting a store where staff are mysteriously “having system issues” whenever you ask. Vodafone’s website has eSIM options buried four menus deep with warnings about “compatibility issues” that don’t actually exist. O2 claims eSIM is “coming soon” – they’ve said this for two years.
Meanwhile, data-only eSIM providers operate entirely online. No shops, no staff, minimal overhead. This translates to prices that traditional networks cannot match without destroying their profit margins.
Which Phones Actually Work
Not every phone supports dual-SIM with eSIM, and the compatibility list isn’t what manufacturers advertise. Here’s what actually works in the UK:
iPhone 13 and newer run dual-SIM perfectly. You can have two eSIMs active or one physical and one eSIM. The iPhone 12 technically supports it but has connectivity issues some users report.
Samsung Galaxy S21 onwards handles dual-SIM, though the S20 has problems with certain eSIM providers. The A-series from A54 upward also works, making this accessible without flagship prices.
Google Pixel 6 and newer excel at dual-SIM, with the cleanest setup process. Pixel 5 supports eSIM but struggles with dual-active mode.
OnePlus 11 and 12 support dual-SIM with eSIM. Earlier models don’t, despite OnePlus claiming they do.
Xiaomi’s situation is messy. Models sold in Europe support eSIM, Chinese imports don’t, even if they’re the same model number. Check the box specifically for “eSIM support” rather than trusting online specs.
Motorola Edge 30 and newer work fine. Older Motorola phones claim eSIM support but frequently fail activation with UK providers.
The Real Cost Breakdown Nobody Shows You
Let’s destroy the myth that contracts save money. iPhone 16 Pro through EE costs £69 monthly for 24 months with unlimited data. Total cost: £1,656. They claim the phone is “only £30 monthly” but that’s creative accounting.
Buy the same phone refurbished from Apple (12-month warranty included) for £899. Add a data-only eSIM at £15 monthly for 50GB. Over 24 months, you spend £899 + £360 = £1,259. That’s £397 less than the contract, and you own the phone outright from day one.
But nobody needs 50GB. Most UK users consume 8-12GB monthly. A 15GB data-only eSIM costs £8 monthly. Now your two-year cost is £899 + £192 = £1,091. You’ve saved £565 versus the EE contract.
Virgin Mobile offers “unlimited” data for £32 monthly but throttles speeds to 10Mbps after 40GB. That’s barely enough for HD streaming. Meanwhile, data-only eSIM providers offer genuinely unlimited data at 5G speeds for £25 monthly because they don’t maintain voice networks.
Three’s famous “unlimited” plan at £35 monthly sounds good until you read the fair usage policy. Hotspot limited to 12GB. Streaming throttled after 100GB. EU roaming capped at 12GB. Their unlimited isn’t unlimited – it’s “unlimited with conditions.”
Setting Up Dual-SIM (The Reality, Not the Marketing)
Networks make eSIM activation sound complex to discourage adoption. The reality? It’s simpler than setting up WhatsApp.
First, check your phone supports eSIM. Settings > About Phone > SIM Status shows eSIM capability. If you see an EID number, you’re compatible.
Order a PAYG SIM from any supermarket network – Asda, Tesco, Sainsbury’s all offer basic plans under £10. When it arrives, insert it and port your existing number. This keeps your WhatsApp, banking apps, and everything else active.
Choose a data-only eSIM provider. UK-specific ones offer better prices than international providers. Some throttle after certain usage, others don’t. Read the actual terms, not the headline offer.
Purchase the eSIM plan online. You’ll receive a QR code via email within minutes. On your phone, go to Settings > Network > Add eSIM. Scan the code or enter details manually if scanning fails (happens 30% of the time).
Label your SIMs clearly in settings. Name the physical SIM “Calls” and the eSIM “Data” to avoid confusion. Set the eSIM as default for mobile data, physical SIM for calls and texts.
Both remain active simultaneously. No manual switching required. Incoming calls use the physical SIM, data automatically routes through the eSIM. Your phone appears to have one number to everyone else.
The Family Plan That Networks Fear
Traditional family plans lock everyone into matching data allowances. Teenagers burn through 40GB monthly, grandparents use 2GB, everyone pays for unlimited. It’s profitable inefficiency by design.
Dual-SIM breaks this model. Each family member gets data matching their actual usage. Parents who mainly use WiFi get 5GB eSIMs for £4 monthly. Teenagers streaming constantly get 30GB for £12. Grandparents who just check Facebook get 2GB for £2.
The Jackson family in Manchester: Two parents, two teenagers, one grandmother. Previous O2 family plan: £150 monthly for unlimited everything. New setup:
- Parents: £5 PAYG + £6 eSIM (10GB each) = £22 total
- Teenagers: £5 PAYG + £12 eSIM (30GB each) = £34 total
- Grandmother: £5 PAYG + £2 eSIM (2GB) = £7 total Monthly total: £63. Annual saving: £1,044.
They keep their phone numbers, keep up with good customer service, and get the ability to modify data to fit a customers needs month to month. Like a teenager going on a trip or holiday? They can pause their eSIM for the month. A grandma visiting for a long time? The family can add temporary data for the whole stay.
What really does go wrong, though.
When it isn’t perfect, we’re not going to pretend like it is.
Wi-Fi calling is one of the pain points with dual SIM. I have heard owners of certain phones say they can’t decide which SIM to use for whatever call, and as a result, it fails. If you’re in an area with a weak signal and rely on Wi-Fi calling, I’d recommend doing your research before going with one of these phones.
Some banking apps will say conflicting things when they see a dual SIM phone for the first time. They will say it’s “modified” and refuse to work. I know Santander and Halifax give users especially a hard time. The fix for this is just disabling one SIM for the time being.
Your emergency services SIM calls can lose some dual SIM functions. The phone can report it’s location to the wrong network. This isn’t too serious, but it’s something to keep in mind.
Visual voicemail is one of those things that usually just stops working. You’ll have to call your voicemail instead; at least this is a minor inconvenience.
Some users say they see a rapid battery drain when they keep dual SIM active. To be fair, this is an older dual SIM technology. Modern phones perform better, but older models can lose an additional 10 to 15% of their battery. Considering the money you’re saving, it makes sense to just get a portable battery for when you’re on the road.
Calling doesn’t switch over smoothly. If you have no service on the physical SIM and your eSIM has service, your calls will not reroute over the eSIM. You have to switch your eSIM manually or call through WhatsApp.
Corporate Response Nobody Expected
Networks had been quiet on the dual SIM feature because they assumed no one would use it. That’s because Ofcom stated in the 2024 report that 400,000 users in the UK had switched to eSIM-only providers.
EE brought on the slogan \”eSIM ready\” while making it more difficult to switch to eSIM. Now they eSIMs require \”verification appointments\” to add more unnecessary friction to the process.
In an attempt to avoid losing customers, Vodafone offered loyalty discounts to customers threatening to leave for eSIM providers. These discounts usually only get close to the eSIM pricing for a short while, then increase after 6 months because they aren’t losing the customer.
O2’s explanation was that they partnered with some eSIM providers to allow \”seamless switching\” which in their words means they get commission from the providers for losing customers, which offsets their lost revenue.
Three, however, still seems to think their customers are happy, boasting their \”truly unlimited\” plans and claiming eSIMs are irrelevant. Their customer loss numbers tell a different story.
Smaller networks were the fastest to adapt. GiffGaff, for example, added proper online eSIMs with reasonable pricing and instant self service activation. Not to mention Smarty’s unlimited eSIMs at a reasonable price. These networks quickly were able to realize that they couldn’t fight the trend.
You’ve Already Made the Switch:
Saving money will always be a personal choice, but the discounts make it worth it. Switching plans is worth it, and the money will be saved.
Check your phone’s eSIM compatibility today. iPhone users, go to Settings > General > About and look for EID. Android users, check Settings > About Phone > SIM Status. If you see eSIM mentioned, you’re ready.
