SIM only deals: the best 6 we've found in the Boxing Day sales

These are the best SIM only deals in the late Boxing Day and early January sales

SIM only deals Boxing Day sales
(Image credit: Three | Voxi | Vodafone | EE)

These are the best SIM only deals available in the Boxing Day sales 2020. These SIM plans offer super affordable and flexible SIMO packages that will instantly transform how you use your handset.

These are SIMO plans that cost a fraction of what with-phone SIM plans cost and deliver orders of magnitude greater allowances, too.

Some of these SIM only deals even manage to offer unlimited data, texts and minutes, as well as completely contract free commitments. You get the best price, best allowances and best freedom as there is no contract involved – you can cancel at any time.

Others offer very strong 5G packages with short contracts at the UK's very best and fastest networks. Basically, there's a brilliant SIM only deal for everyone right here – and especially as price start at just £12 per month.

Here are the best SIM only deals available this Boxing Day:

Star Deal

Three SIM only | Unlimited data, texts and calls | £16 p/m | Contract length: 12 months | Available now at Three
Three's 5G ready SIM here delivers unlimited data, minutes and texts for just £16 per month, which is £2 per month cheaper than the Smarty deal above. This plan does come with a minimum term contract though of 12 months, which while short does not offer the same walk-away freedom as the Smarty deal above.View Deal

Smarty SIM only | One month rolling plan | Cancel anytime |  Unlimited data | Unlimited calls and texts | £20/month
The Three SIM only deal above is technically cheaper, but this Smarty plan is still worth considering as it delivers unlimited everything with no contract. That's right, this is a cancel at anytime deal, meaning you can walk away at any time. £20 per month for unlimited everything. Super value.View Deal

Vodafone SIM only | 100GB data | Unlimited calls and texts | 12-month plan | £16 per month
Here's a very tidy SIM only deal that can be bagged right now over at It delivers a SIM plan with a 12-month contract that offers a whopping 100GB of data to burn each month, along with unlimited calls and texts. The monthly fee is a very affordable £16, which is then reduced to just £11.50 with a cashback program.View Deal

Smarty SIM only | 1 month rolling plan | 50GB data | Unlimited calls and texts | £15 per month
Here's another great contract-free SIM plan from Smarty that delivers freedom to walk away whenever you want. This one delivers 50GB of data and unlimited calls and texts for just £15 per month.View Deal

Voxi SIM only | 1 month rolling plan | 12GB data | Unlimited calls and texts | Endless Video | £102 per month
Voxi loves its Endless offers, and this 12GB for £10 per month SIM only deal offers Endless Video and Endless Social Media, meaning you can stream endlessly on YouTube and video apps as well as engage on social media platforms without touching your data allowance, which is 12GB per month. £10 for 12GB is great value.View Deal

EE SIM only | 24-month contract | 200GB data | Unlimited calls and texts | £23 per month
EE is the UK's fastest mobile network, and its SIM plans come with lighting fast 5G data capabilities unlocked. Right now EE's 5G Essential Plan is only £23 per month, and it delivers a huge 200GB of data each month along with unlimited calls and texts. You also get free EU roaming and 6 months free of Apple Music. This comes on a 24-month contract, however.View Deal

To compare these SIM only deals to the rest of the market be sure to take a look at T3's SIMO deals comparison tool below. This not only surfaces the very cheapest SIM only deals, but also lets you filter them by a wide-variety of things, such as contract length, price, data allowance, network coverage, 5G and more.