Best 20GB+ SIM-only deals
SIM-only deals with at least 20GB of data. Ranked by true monthly cost, which includes intro offers ending and April price rises. Updated daily.
SimSift may earn commission if you take a deal through our links. It never changes how deals are ranked. How we make money.
| Network | Data | Contract | True monthly cost | £/GB | Action |
|---|---|---|---|---|---|
| Network A on Vodafone |
20GB | 30-day | £5.50 £66.00 total | £0.28 | Live prices soon |
| Network I on EE |
20GB | 30-day | £6.90 £82.80 total | £0.35 | Live prices soon |
| Network K on Vodafone |
40GB | 12 months | £6.95 £83.40 total | £0.17 | Live prices soon |
| Network B on Three |
120GB | 12 months | £7.31 £87.75 total | £0.06 | Live prices soon |
| Network C on Three |
75GB | 30-day | £8.00 £96.00 total | £0.11 | Live prices soon |
| Network H on Vodafone |
70GB | 12 months | £9.75 £117.00 total | £0.14 | Live prices soon |
| Network D on Vodafone |
60GB | 30-day | £10.00 £120.00 total | £0.17 | Live prices soon |
| Network E on O2 |
35GB | 30-day | £10.00 £120.00 total | £0.29 | Live prices soon |
| Network L on O2 |
50GB | 12 months | £10.00 £120.00 total | £0.20 | Live prices soon |
| Network F on O2 |
50GB | 12 months | £10.25 £123.00 total | £0.20 | Live prices soon |
| Network G on Three |
100GB | 24 months | £12.30 £295.20 total | £0.12 | Live prices soon |
| Network M on EE |
100GB | 12 months | £13.25 £159.00 total | £0.13 | Live prices soon |
| Network C on Three |
Unlimited | 30-day | £16.00 £192.00 total | — | Live prices soon |
| Network A on Vodafone |
Unlimited | 30-day | £19.00 £227.94 total | — | Live prices soon |
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SIM-only FAQs
What is the true monthly cost of a SIM-only deal?
It is the total you pay over the contract (including introductory prices ending and any annual April price rises) divided by the number of months. 30-day rolling plans are costed over 12 months.
How does SimSift rank deals?
By true monthly cost, lowest first. Commission never changes the order, and every affiliate link is labelled.
How does SimSift make money?
Some networks pay us a commission through affiliate networks such as Awin when you take a deal via our links. It costs you nothing extra.
Can I keep my number when I switch?
Yes. Text PAC to 65075 for free to get your porting code, then give it to your new network. The switch normally happens within one working day.
Will I get good signal?
Check coverage at your postcode with Ofcom's mobile checker before switching. Many smaller networks run on the O2, Vodafone, Three or EE networks, so coverage matches the host network.