More data.
Much less money.
Cheapest SIM deals we compare, ordered by price. From £5 per month for light users to £22.50 for unlimited data. Find the best deal for your budget.
The cheapest SIM only deals we compare start from £5 per month with Lebara for 5GB on Vodafone. For the best value on a decent data allowance, giffgaff's 40GB plan at £10 per month on O2 with no contract is hard to beat. For a 12-month contract, Lebara's 30GB plan at £9 per month is excellent value.
Cheapest SIM deals we compare, sorted by price
Lebara 5GB (30 day)
Asda Mobile 10GB (24 month)
giffgaff 40GB (30 day)
giffgaff 75GB (30 day)
Lebara 100GB (12 month)
Lebara Unlimited (12 month)
Why budget SIM cards are just as good as expensive ones
The thing most people do not realise is that cheap SIM providers run on exactly the same infrastructure as EE, O2, Vodafone, and Three. giffgaff uses O2's network. Lebara and Asda Mobile use Vodafone's. The signal you get at your front door is identical. The only difference is you are not paying for the high street stores, the TV adverts, and the brand premium.
This is why switching to a budget MVNO is almost always a straightforward win for anyone currently on a major network contract. The coverage is the same. The calls work the same. The only thing that changes is the monthly bill.
How to actually find the cheapest SIM for you
The cheapest SIM is not always the one with the lowest monthly price. It is the one with the best price per GB for how much data you actually use. Paying £5 per month for 5GB sounds cheap, but if you use 40GB a month and run out halfway through, you are worse off than paying £10 for 40GB.
The cards above show the price per GB alongside the monthly price. The Lebara 30GB 12-month plan at 30p per GB and the giffgaff 75GB plan at 16p per GB are genuinely strong value per gigabyte. The cheapest absolute price per month is not always the cheapest in practice.
The other thing worth checking before you switch is coverage. A cheap SIM on a network with weak signal where you live is not a good deal. Check Ofcom's coverage checker or the specific network's coverage map at your home address and your main locations before committing. See our full SIM only comparison for the complete range.
Questions people ask
The cheapest SIM only deals start from £5 per month with Lebara for 5GB on Vodafone. For a no-contract plan with a decent allowance, giffgaff's 40GB plan at £10 per month on O2 is the best value. On a 12-month contract, Lebara's 30GB plan at £9 per month is hard to beat.
Yes. Budget SIM providers run on the same network infrastructure as the major operators. giffgaff uses O2's network. Lebara and Asda Mobile use Vodafone's. The coverage and signal you get is identical. The only difference is the price.
Choose a plan from this page, click through to the provider, and sign up. Your SIM arrives in the post within a few days. If you want to keep your existing number, ask your current provider for a PAC code before you switch and give it to your new provider when you sign up.
Lebara's 12-month Unlimited plan at £22.50 per month is the cheapest unlimited SIM on a contract. For no-contract unlimited data, Chattr at £20 per month on O2 is the standout. Asda Mobile's unlimited plan at £19 per month is the cheapest unlimited SIM overall but requires a 24-month commitment.
Look at price per GB rather than just the headline monthly price. Check coverage at your home address and regular locations before switching. Consider contract length, a 12-month plan is cheaper per month but a 30-day rolling plan gives you flexibility. The cheapest monthly price is not always the best overall value.
Related deals and guides
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