Mobile · Provider guide
Three SIM-only deals: every plan and the real cost
Three has 3 deals in our table on 25 Oct 2026, from £8.00 a month. The best value is 20GB Lite plan at a real cost of £11.90 a month (20GB data · Three network · 24 months). Its stated price rises are built into every real cost below.
Best-value Three plan
Three 20GB Lite plan
20GB data · Three network · 24 months · £11.90 a month real cost
The lowest real cost here from a national provider on 25 Oct 2026, with fees and stated price rises counted.
Every Three deal we track
Checked 25 Oct 2026| Provider and package | Data | Contract | Monthly price | Real cost | Deal |
|---|---|---|---|---|---|
Three 20GB Lite plan Three+ Rewards · Monthly price includes a £5 discount for paying by Direct Debit | Data20GBThree network · 5G | Contract24 monthsEU roaming included | Monthly price£10.00£11.90 from 1 Apr 2027, then £13.80 | Real cost£11.90 /mo£285.60 over 24 months | See deal at Three (opens in a new tab) |
Three 120GB Lite plan Three+ Rewards · Monthly price includes a £5 discount for paying by Direct Debit | Data120GBThree network · 5G | Contract24 monthsEU roaming included | Monthly price£8.00£18.30 from 1 Apr 2027, then £20.60 | Real cost£16.30 /mo£391.20 over 24 months | See deal at Three (opens in a new tab) |
Three Unlimited Lite plan Three+ Rewards · Monthly price includes a £5 discount for paying by Direct Debit | DataUnlimitedThree network · 5G | Contract24 monthsEU roaming included | Monthly price£22.00£24.30 from 1 Apr 2027, then £26.60 | Real cost£24.30 /mo£583.20 over 24 months | See deal at Three (opens in a new tab) |
Ranked by real cost; commission never changes the order. Prices checked on each provider's own site on 25 Oct 2026.
Who Three suits
Three SIM-only plans suit people who want lots of data, 5G and EU roaming.
Our table lists 3 Three plans, from 20GB to unlimited data. Every plan includes 5G, the newest mobile network technology, and EU roaming, which lets you use your data in EU countries. Heavy data users such as streamers, gamers and frequent travellers get the most from them.
Plans in our table run on 24-month contracts. That suits people who are happy to commit for two years. If you want to leave with a month's notice, a cheapest SIM-only deal on a 30-day SIM may suit you better.
If you use little data, a smaller plan from another network may fit you better. Check your data use in your phone settings before you choose.
Network and coverage
Three SIM-only plans run on the Three network. Three is part of VodafoneThree, the merged Vodafone and Three UK business.
Every UK SIM-only brand runs on one of four networks: EE, O2, Vodafone or Three. Brands on the same network share its coverage. So the host network often matters more than the brand name.
Every Three plan in our table includes 5G, the newest mobile technology, where your area has it. Check Three's coverage for your postcode before you sign. Want a different network? Compare EE SIM-only deals, O2 SIM-only deals or Vodafone SIM-only deals.
What it really costs
Our Three SIM-only deals run on 24-month contracts, so the real cost covers two full years.
Three states its mid-contract price rises in pounds on its deal page. Our table adds them in, so you see the true total before you sign. Since 17 January 2025, Ofcom rules require any price rise in a new contract to be shown in pounds and pence.
**The monthly price already includes a £5 discount for paying by Direct Debit.Sort the table by real cost, cheapest first, to compare Three plans side by side. To check other networks, see our cheapest SIM-only deals.
Straight answers
Questions people ask
- Is Three good value?
- Three can be good value if you want 5G and EU roaming included in your plan. Our table ranks Three's three SIM-only plans, from 20GB to unlimited data, by real cost. Sort by real cost, then compare the top plan with other networks before you decide.
- What network does Three use?
- Three SIM-only plans run on the Three network. Three is part of VodafoneThree, the merged Vodafone and Three UK business. Three plans include 5G. Any SIM-only brand on the Three network shares that network's coverage.
- How do I switch to Three and keep my number?
- To switch to Three and keep your number, text PAC to 65075 from your current phone. You will get a code. Give that code to Three when you sign up, and your number moves in one working day.