Cheap SIM only deals in December 2023: the best budget SIM cards

Cheap SIM only deals hero image

A cheap SIM only deal is the best option to save money if you’re happy to keep using your current phone.

Want to learn more about how to get the best SIM only deal without breaking the bank? We’re going to arm you with all the info you need, as well as a breakdown of which networks offer cheap SIM contracts. Keep reading to get all the juicy details. 

How to find a cheap SIM only deal

Finding a cheap SIM only deal is easier than it may sound. UK networks all want to sign you up to their plans, so there’s a lot of healthy competition going on. As such, SIM providers big and small – from giffgaff to O2 to Three to Lebara – are always lowering their prices and launching new deals with incentives and extras in a bid to get new customers. 

Let’s take a look at what you can find on the market. 


£5 SIM deals

Are you looking for the cheapest possible SIM-only deals? There are loads of deals for people looking to save cash, with budget-friendly networks providing deals for as little as £5 per month. 

And just because a deal is cheap it doesn’t mean you’ll be losing out on quality. Even budget networks usually send out SIMs that are 5G-ready for no additional cost. So your mobile speed won’t be left behind.

Take a look at these networks for the best low cost deals:

Which networks offer cheap SIMs?

You don’t have to go very far to find a cheap SIM only deal. And if you’re keen to compare offers, you’ll be delighted to know that practically all the top UK mobile phone networks provide cheap SIM deals in one way or another. Whether that’s a great value long-term deal or a convenient 30-day plan, there’s plenty of choice available. 

Here’s a look at what you can expect from the best brands:

Cheap Vodafone SIMs

Vodafone’s cheap SIM only deals start from as little as £7 a month for 6GB of data. Or you can pay up to £31 per month for unlimited data. You can sign up for 12, 24 month or rolling  monthly deals. And you’ll get better rates if you sign up for longer. That said, you won’t have the flexibility of a 30-day plan.

Vodafone SIM only customers can also take advantage of the VeryMe Rewards programme. Enjoy offers, giveaways, freebies and discounts from high-street stores and big brands.

If you’re in a 5G area with a 5G phone, you can get 5G for no extra cost, too. 

Cheap Three SIMs

Three’s reputation as one of the UK’s best networks is built on years of affordable deals and excellent service. Currently, it’s offering a great 12-month SIM deal where you can get 12GB of data for just £6 a month. Three covers all bases with its plans. If you’d like more data, or would prefer a 30-day deal, those options are available for you too.

Three’s SIMs are all 5G ready. And you can enjoy a host of benefits thanks to the Three+ loyalty app. This gives you exclusive freebies and discounts from stores and services like Caffe Nero, Cineworld and Uber Eats. 

Cheap O2 SIMs

Like other top networks, O2 has a wide selection of SIM deals on offer. Its cheapest deal is currently a 12-month plan that includes 20GB of data for only £8 per month. Which is very attractive for a fairly heavy data user. O2 offers monthly rolling contracts too. But you’ll likely find better value in its longer deals. 

And since O2 is one of the biggest names in the business, you can look forward to exciting perks and bonuses when you get a SIM only deal. Most plans enable you to add on an O2 Extra for free. This can include a subscription to Disney Plus or Apple Music. 

You also get first dibs on a range of event tickets thanks to O2 Priority. And O2 is one of the only UK networks that hasn’t reintroduced EU roaming charges. So you won’t need to pay extra to use your O2 SIM anywhere in the EU.

Cheap Lebara SIMs

It’s hard to beat Lebara when it comes to cheap SIMs. This network’s selection of keenly priced deals can cost as little as £4.50 a month for a rolling 5GB data plan. Its focus is on simple, flexible SIMs. So you’ll never have to sign up to a long contract or even pass a credit check. 

Lebara also has a unique selling point that will appeal to people looking to keep in touch with family and friends overseas – inclusive international minutes. Unlike the majority of other networks, Lebara allows you to use your minutes to call people in 41 countries for no extra charge. 

And with the list covering locations like Australia, most of Europe, the US and parts of Asia, frequent overseas callers could save a lot of money with a Lebara SIM deal.

Cheap giffgaff SIMs

There are plenty of cheap SIM only plans offered by giffgaff. And if you’re willing to sign a long-term contract, you’ll get more value for your money.

But if you’d rather keep it flexible, giffgaff offers 30-day rolling plans that you can cancel or switch whenever you like. 

Currently, giffgaff’s cheapest SIM only deal is £6 per month for 2GB of data on a rolling plan. If you want more data but still would like to save money, you can jump up to 25GB for £10 a month on an 18-month contract. 

Cheap iD Mobile deals

iD Mobile provides a wide range of plan durations and data allowances. You can sign up for 30-day rolling plans or go longer term for 12 or 24 months.

Its SIM only plans also include useful features such as data rollover. Any data you haven’t used up at the end of the month will get carried over into the following month so you won’t lose it. 

What to look for with a cheap SIM

Data allowance

The most important thing to consider when signing up for a cheap SIM deal is how much data you need. If you blaze through your monthly GB allowance by streaming and scrolling throughout the day, you’ll be suited to a large data deal. And with most networks offering ranges from anywhere in between 20GB to unlimited, you won’t be short of options. 

On the flipside, networks cater for low level users too. So if you find that you’re usually connected to Wi-Fi, you can save money by sticking to a plan of say 5GB a month. 

The trick is to not pay for too much (or too little). That way, you’re not overspending for no reason nor will you ever run out or get additional charges. So along with thinking about how you use your phone, check out your current network’s app or online account service, and you should be able to see exactly how much data you’ve been using on a monthly basis. 

Contract length

The duration of your deal is another important factor in terms of pricing (and flexibility). Networks tend to offer you better value if you commit to a long term plan (12 months or more). But then you’re locked in to pay a set amount every month. 

Shorter deals, which often operate on a monthly rolling basis, are a popular alternative. Not only do they give you the freedom to change your data allowance and spend as often as you want, they also won’t require you to complete a credit check. So they’re simple and fuss-free.


If you love a freebie (and let’s face it – who doesn’t?) you should look out for a SIM deal that bundles in some extras too. You’ll find that these are common with the bigger name brands of the mobile world. 

For instance, O2 has been providing exclusive early access to superstar concerts and events for years. And with online ticket sales increasingly becoming a breakneck race to secure the checkout, getting a step ahead could be a gamechanger if you’re a regular gig goer. 

Other big networks like Vodafone and Three also offer rewards and exclusive offers to their customers on famous brands and entertainment products.


EU roaming used to be free on all networks. But since Brexit, more and more networks have bought back roaming charges.

If roaming is important to you, check which networks are currently offering inclusive roaming (such as O2 and SMARTY). Also take a look at their fair usage policies to make sure you don’t get caught out.

Cheap unlimited data SIMs

If you want a SIM only deal that’s free from data restrictions, an unlimited plan is what you need. Luckily, most of the top networks – such as O2, Three, Vodafone, VOXI, and more – offer unlimited data packages. And unlimited data deals are getting cheaper all the time, so you should be able to bag yourself a bargain.


Is it cheaper to get a SIM only plan?

Yes, SIM only deals will always be cheaper than pay monthly mobile phone plans. That’s because you’re only paying for your data, call minutes and messages. 

With smartphones holding their value for longer than ever, switching to SIM only is a great way to save money and reduce your monthly bills once you’re out of contract. 

Will there be a credit check on my SIM only plan?

Not always. If you opt for a long-term SIM only plan (12 months or longer), you will likely have to complete a credit check. But the good news is there are plenty of cheap SIM only deals that are monthly rolling plans. And these don’t require a credit check.

Is pay as you go cheaper than a pay monthly SIM?

No, pay as you go will work out to be more expensive than a SIM only deal if you use your phone regularly. That’s because pay as you go rates are always more expensive than SIM only deals.

And every call or text you make will whittle down your money. SIM only deals, on the other hand, usually give you unlimited calls and texts for as little as £5 a month.

Can I keep my number when I get a new SIM?

Yes, you can always keep your number when you switch to a new SIM only deal. All you need to do is send a text to 65075. You’ll receive a reply within a couple of hours containing your PAC code. You then just need to send to your new network for them to easily port over your current phone number when you get a new deal.

Can I buy a SIM without a plan?

Yes, may networks offer SIMs that aren’t attached to a plan. Some even provide them for free. You’re then able to choose a plan at a later date and activate the SIM when you’re ready.