January Sale SIM only deals: best offers on each network
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We guide you through the best SIM only offers in each UK mobile network's January Sale for every data requirement, budget and provider. SIM Sherpa is your trusty guide. Last updated: 8th January 2021
In our January Sale SIM only deal guide
Most networks have some kind of winter sale live
We'd say the post-Christmas period is the second best time in the year to get a bargain on a new SIM only plan (after Black Friday). And loads of networks have their January Sale offers live.
See our best-rated deals here, where we find the best offers per data amount
See offers by mobile network here, if there's a particular provider you want to join
This Virgin offer (on EE) is daft value at the low-end of price and data usage but only lasts until 4th January:
Talkmobile's (on Vodafone) triple data offer is our favourite mid-range deal and lasts until 4th January:
In the large data category, we like this automatic cashback offer from mobiles.co.uk (unknown end date):
£30 auto cashback by cheque 
And for unlimited data, we'd be choosing between SMARTY and Three's hidden offers:
We hope you enjoy our guide and find a great deal.
Our best-rated offers
January Sale SIM only offers
We've broken down the best deals into categories:
Unlimited data offers
✔ Three's hidden offer is the best deal
We've got a hidden £16 deal here from Three, which beats even their 6 months half price sale offer running currently for price. This isn't advertised on the main part of Three.co.uk:
For a wholly different network, we like this Vodafone SIM only deal that mobiles.co.uk are offering. They'll send you a cashback cheque through the post without having to claim and it's Vodafone's full-speed 5G plan:
Otherwise, have a look under the dropdown for other networks' best deals during the January Sale period:
If a network's not here, it's because they don't do unlimited data:
Useful link: Compare all unlimited data plans here
Deals with 50GB or more
✔ Decent sale offers, even on the main networks
Mobiles.co.uk have got a really nice deal again here if you want to join Vodafone. Not only do you get an exclusive low price for 100GB but they'll also send you a cashback cheque, without you having to claim one:
This cheaper Talkmobile deal also uses Vodafone but without extras like WiFi calling or 5G data:
This Virgin SIM only deal is the cheapest option to get on the EE network:
Unless you have BT broadband, in which case have a look at this offer, which lasts until 4th February:
If you remember to compare once this O2 deal is up, so you don't pay full price too long, we think this 6 months half price January Sale offer is decent, when you order by 10th February:
Here are each UK network's best SIM only plans with 50GB or more data. If their unlimited plan is still cheaper, we'll include it here:
Useful link: Compare all plans
Offers with 20GB+ data
✔ Plenty of decent offers
It's not even specifically a January Sale offer but SMARTY's SIM only deal below still leads the pack on price in this category:
If you've got BT broadband at home, this is exceptional value on the EE network (ends 4th Feb):
Or SMARTY's parent Three have a decent hidden offer here too:
For a deal on the EE network, Virgin's triple data offer here compares well, as long as you're happy to commit to that 24-month contract:
Or for a deal on O2, this 3 months half price Tesco Mobile offer is worth a look too:
These are the best current SIM only plans on each network with 20GB or more data. If they've got a plan with more than 20GB that's still cheaper, we'll include it here:
Useful link: Compare all plans
Offers with 10GB+ data
✔ Big value from multiple providers
There's lots of similar deals floating around in this data category. You can basically take your pick, which network you want to be on.
For Vodafone, Lebara's 3 months half price offer here lasts until 31st January:
On the Three network, this hidden offer is better value than advertised directly:
On the EE network, Virgin Mobile once again have the best-value offer:
On the O2 network, Tesco have the best value:
These are the best SIM only offers available from each network with 10GB or more data. If there's a cheaper deal that comes with more, we'll show that instead:
Useful link: Compare all plans
5GB+ SIM only deals
✔ Lots of overlap with bigger plans
Plusnet are offering excellent value when you order by 20th January. You don't have to have their broadband to get this pricing and they run on the EE network:
We also think iD Mobile have got a really good deal in this category here, which is only a 1-month contract:
Or this Talkmobile offer on the Vodafone network works out cheaper if you're happier with a longer deal:
Sky Mobile's double data offer here is decent too and uses the O2 network (order by 25th February):
Otherwise have a look in the section above, because some of those offers beat the rest of what's available. Or there's the dropdown below:
If you want at least 5GB with you deal, here's each network's best efforts. If they're offering more data than that for less, we'll still include it:
Useful link: Compare all plans
Deals with 3GB to 4GB
✔ Serious value on certain providers
Virgin Mobile are offering decent value with this 3GB for £6 deal:
This Three offer is hidden and isn't advertised on the main part of their website. It's even better than Virgin's but on a different network and includes 5G if your phone supports it:
For a deal on the Vodafone network, Talkmobile's 3 months half price offer is a nice option too:
These are each network's 3GB and up SIM only offers at the moment. If they're offering more data without it costing extra, we'll still include it:
Useful link: Compare all plans
1GB to 2GB offers
✔ Low prices from the smaller providers
If you're not fussed about unlimited minutes, this Lebara offer is half price for the first 3 months when you order by 31st January:
Or to also get unlimited minutes and texts but slightly less data, this iD Mobile one (on Three) is worth a look:
Or you can get this with Talkmobile who use the Vodafone network:
Here's the best SIM only plan with 1GB or more on each network at the moment. If they include more without charging more, we'll still include it:
Useful link: Compare all plans
January Sale offers by network
Choose a mobile network
Three: hidden offers on SIM only
Three have actually kept all the same offers running into January that were live over Black Friday, so it's still an excellent time to order. Here's a look at what's available now:
We're not expecting any of the Three's non-hidden sale offers to beat these deals, so you should be safe to order, even if Three haven't launched their January Sale for real yet.
Useful link: Our Three review
BT Mobile: double data January Sale offers
Expected date: 8th January 2021
Expected end date: 4th February 2021
Order now or wait? Safe to order
The key standout offers in BT's January Sale on SIM only are their 24-month double data ones below, which are available up until 4th February:
If you don't need that much data, this is a decent offer on a shorter contract too:
Useful link: Our BT Mobile review
EE: just a couple of January sale offers
Launch date: 5th January
End date: Unknown
Order now or wait? Safe to order
EE have made some minor improvements on their existing range of SIM only deals for their January Sale, with two standout deals in the extra large data category:
For smaller data deals, have a look at EE's Triple Data offer on their Flex SIMs (1-month, no contract plans). It's not a specific January Sale offer but they do offer better value with no commitment.
Useful links: Our EE review | Our guide to Flex Plans
giffgaff: we don't expect and January Sale SIMs
Launch date: N/A
End date: N/A
Order now or wait? Safe to order
giffgaff never tend to do anything promotional on their SIM only plans at key periods like during January sales. They tend to focus on phone contract discounts instead.
That means we suspect you're safe to order now with them and not have a better offer come along in January that you'd miss out on. Order via our invite page and you'll get £5 free credit with a £10 top up.
For us, their standout offer is this:
But there are more deals under the dropdown below:
Useful link: Our giffgaff review
iD Mobile: 3 months half price sale offers
Launch date: 23rd December 2020
End date: 20th January 2020
Order now or wait? Safe to order
iD are hoping to coax you into some longer 12-month deals with 3 months half price on multiple plans when you order by 20th January. This the best of those:
We still think iD's main strength is their 1-month plans though, including this hidden offer for just £5:
And this generous 5GB for just £7 deal:
Useful link: Our iD Mobile review
O2: some decent offers including 6 months half price
Launch date: 26th December 2020
End date: Depends on plan
Order now or wait? Depends on plan
Since O2 stopped selling via Carphone Warehouse, they've started hitting their offers on SIM only a bit harder. Their Winter Sale in now live and there's some decent deals to be had.
Their headline offer is this 6 month half price SIM, which works out at £16.67 on average over the course of 18 months, but remember to compare again at the end to avoid paying the higher price too long:
Useful link: Our O2 review
Plusnet Mobile: decent value in their SIM only sale
Launch date: 31st December 2020
End date: 20th January
Order now or wait? We'd wait
Plusnet's winter sale on SIM only is now live, with some better-than-average offers, which last until 20th January.
This 10GB for £8 offer is excellent value, especially if you have their broadband as you'll get an extra 2GB on top for no extra cost:
This is also good value on its own. And even better for their broadband customers to get 5GB for just £6:
Useful link: Our Plusnet Mobile review
Sky Mobile: one competitive offer in their sale
Launch date: 23rd December 2020
End date: 25th February 2021
Order now or wait? Safe to order
The Sky Mobile Sale lasts right into February, with their main double data offer below available until 25th February. It's currently the best value 6GB+ with a provider on the O2 network:
Their other offers in the sale are decent value historically for Sky but are beatable, even on O2 directly:
Useful link: Our Sky Mobile review
SMARTY: loads of great non-sale offers
Launch date: Varied per plan
End date: Varies per plan
Order now or wait? Safe to order (wait if you want 50GB)
We don't expect SMARTY to have a big sale event with discounts across all their plans, mainly because they're all priced so low the rest of the year anyway.
This is the best 1-month mid-range data deal on the market (unknown end date):
And this ongoing deal, which isn't a sale offer, is still knocking out all the competition, even a year after its initial launch:
An exceptional set of offers from SMARTY for January.
Useful link: Our SMARTY review
Talkmobile: quite a few different offers
Launch date: Depends on plan
End date: 4th-27th January 2021
Order now or wait? Safe to order
Talkmobile's headline offer is 3 months half price on a range of their 12-month contracts but their actual individual best SIM only deals fall between the cracks of that offer.
We still really like this hidden 1-month deal, which is the joint-cheapest on the UK market and ideal for basic users. It's got no known end date:
And this compares very well for big data users too:
Useful link: Our Talkmobile review
Tesco Mobile: 3-month half price sale SIMs
Launch date: 30th December 2020
End date: Unknown
Order now or wait? We'd wait
Tesco Mobile's SIM only sale is live and gets you 3 months half price on these plans:
Useful link: Our Tesco Mobile review
Virgin Mobile: January flash sale live now
Launch date: 23rd December 2020
End date: Unknown
Order now or wait? Safe to order (otherwise wait)
If you're in the market for a low-cost SIM with as much data as possible, Virgin's deal below is market-leading but is only available until 4th January:
This is the best-priced deal on the EE network in the mid-range of data currently:
And this is an excellent deal too for bigger data users:
Useful link: Our Virgin Mobile review
Vodafone: automatic cashback with Mobiles.co.uk
Launch date:8th January
End date: Unknown
Order now or wait? Safe to order
Vodafone's Big Winter sale is on if you're buying directly at vodafone.co.uk but we'd recommend having a look at Mobiles.co.uk's automatic cashback deals too. You get a cheque through the post without having to claim on these:
We're unsure of the end date for both these deals.
Useful link: Our Vodafone review
VOXI: double data and money off unlimited data
Launch date: 29th December
End date: 25th February
Order now or wait? Safe to order
VOXI's Winter Sale is live and it seems them add double data to their entry-level plan, which now comes with a handsome 12GB for £10 on just a 1-month deal:
And their other sale offer is a modest £5 off unlimited data, which is 5G-ready as long as your phone is too:
Both offers last until 25th February.
Useful link: Our VOXI review
Compare all current SIM only deals
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