Three's £20 unlimited data SIM only deal: how to get it at the lower price
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It's still possible to get Three's unlimited data SIM only plan for just £20 a month. We show you how, and look at the plan's other benefits. SIM Sherpa is your trusty guide. Last updated: May 23rd 2019.
What's the deal?
Unlimited everything for £20 a month (4.5/5)
It's unlimited data. And it's priced at £20 (if you're willing to commit to a 24-month contract). There is no cheaper unlimited everything SIM on the market.
Plus you get Three's usual benefits of 99% 4G population coverage, inclusive roaming and perks like free easyJet upgrades and their daily rewards app, Wuntu.
Useful link: Read full benefits below
Or it's £2 more if don't want to commit to such a long deal:
What's good about it?
It's genuinely unlimited data - and that's pretty rare
If you've ever put your phone down because you're worried about going over you data usage limits, Three's unlimited data SIM puts an end to that. You're free to use as much as you like in the UK at no extra cost.
And you're not limited by any sneaky traffic management or throttling rules when you use it in this country either. Others sometimes promise no data caps but then slow you down to stop you using too much.
You can also use it for tethering (personal hotspot), which is where you connect tablets or laptops to your phone so they can access internet anywhere you have mobile signal. That's unlimited in the UK too.
The only restrictions come when you're using your SIM abroad. There, you won't be able to use tethering, a monthly cap of up to 19GB applies (depending where you are) and Three reserve the right to slow down your connection while roaming.
Useful link: Three's terms and conditions
Three's network offers good 4G coverage and speeds
✔ Make sure you'll be able to use unlimited dataCheck Three's coverage
at Three.co.uk
(opens in new window)
It's true that Three aren't the UK's largest network but they now put their 4G coverage as reaching 99% of the population in the places where they live. There's still work to do in rural locations.
We'd always recommend checking any network's coverage before you sign up. Use Three's official network map here to do so. Be sure to look not just at home but anywhere you'll be using your phone.
Over 4G, we'd expect Three customers to get download speeds of around 20 Mbps on average, which currently puts them in joint second with Vodafone behind EE.
This is a healthy score that is similar to what many will be getting home over non-fibre broadband. It'll support smooth video and audio streaming and let you browse the general internet
Useful link: Check Three signal in your area
The £20 price smashes Three's competition out of the park
The only other mobile networks to offer truly unlimited data are SMARTY on a £25 1-month deal and Virgin Mobile on a £27 12-month deal (but you need to be a Virgin Media TV or broadband customer to buy it).
Otherwise, for around £20 a month on a 12-month contract with other mobile networks, you are looking at deals with capped data allowances and you could end up spending more:
Useful link: Use our SIM only deals comparison tool
It's Three's best price we see for unlimited data nowadays
We monitor Three and other mobile networks' offers constantly. The £20 price was available three times in 2018/19 on the 12-month SIM, most recently until 16th May.
The 12-month price has now gone up to £22 a month. This is still a low price historically. Three have previously charged £32, £29 and £27 for the plan in the last years.
Three's 24-month SIMs have only just launched. So there's no historical pricing available.
We haven't seen 12-month unlimited data on Three priced below £20 a month for many years.
Useful link: See Three's SIM only deals page