The best SIM only deals in the UK, compared.
Stop overpaying for your phone plan. Compare SIM only deals from leading UK networks and find the right allowance at the right price for how you actually use your phone.
The best SIM only deal in the UK right now depends on what you need. For overall value on a 12-month contract, Lebara's 100GB plan at £18 per month on Vodafone is the standout. For a no-contract flexible plan, giffgaff's 40GB at £10 per month on O2 leads the market. For unlimited data, Lebara's 12-month unlimited plan at £22.50 per month is the cheapest available.
Best SIM only deals right now
giffgaff 40GB (30 day)
Lebara Unlimited (12 month)
Chattr Unlimited (30 day)
Asda Mobile Unlimited (24 month)
Lebara 5GB (30 day)
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How to choose the right SIM only deal
The single most important question is how much data you actually use. Check your current phone's settings to see your average monthly data usage before you choose a plan. Most people dramatically overestimate how much they need, especially if they are on home or work WiFi for most of the day.
The second question is how long you want to commit. A 12-month contract is cheaper per month but ties you in. A 30-day rolling plan costs a little more but you can switch or cancel any time. If you are uncertain about your usage, your network, or your situation in the next year, the rolling plan is worth the small premium.
The third thing most people overlook is which network the SIM runs on. Budget providers like giffgaff, Lebara, Asda Mobile, and Chattr do not own their own masts. They rent capacity from O2 and Vodafone. The coverage you get is effectively the same as the parent network. If you know O2 has strong signal where you live and work, giffgaff or Chattr will too. If Vodafone is stronger in your area, Lebara or Asda Mobile are the better picks.
SIM only vs phone contract
If your current phone is working fine, switching to SIM only is almost always the smarter financial decision. A typical phone contract charges £50 to £80 per month. A SIM only plan with the same or more data costs £10 to £25 per month. The difference over 24 months is significant.
The only reason to stay on a phone contract is if you want a new handset and prefer to spread the cost. In that case, compare the total cost of the contract over its full term against buying the phone outright and getting a SIM only plan. You will usually find the contract costs more in total, though the lower upfront cost is convenient. See our phone and SIM hub for phone contract options too.
Questions people ask
For overall value on a 12-month contract, Lebara's 100GB plan at £18 per month is the standout. For no-contract flexibility, giffgaff's 40GB plan at £10 per month leads the market. For unlimited data, Lebara's 12-month unlimited plan at £22.50 per month is the cheapest available. The right answer depends on your data needs and how long you want to commit.
A SIM only deal gives you a SIM card with a monthly allowance of data, calls, and texts but no handset. You use your existing phone. Because you are not paying off a device, SIM only plans are significantly cheaper than phone contracts. They come on 30-day rolling or 12-month terms.
Yes, almost always. SIM only plans cost £10 to £25 per month for generous data allowances. The same data on a phone contract with a new handset typically costs £40 to £80 per month. If your current phone is working well, switching to SIM only is almost always the right financial move.
If you want to keep your number, ask your current provider for a PAC code before you switch. Give it to your new provider when you sign up and your number transfers automatically, usually within one working day. If you do not need to keep your number, simply sign up to a new plan and your SIM arrives in the post within a few days.
A 12-month plan is cheaper per month and suits people who know which network they want and are settled for the year. A 30-day rolling plan costs slightly more but gives you complete flexibility to switch or cancel any time. If you are uncertain about your usage or situation in the next year, the 30-day option is worth the small premium.
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