Cheapest SIM only deals in March

Featured cheapest SIM-only deals

Below are some of the cheapest SIM-only deals currently available. These plans focus on keeping the monthly price low while still offering a practical data allowance.

Cheap SIM-only plans are commonly available with:

• Small to medium data bundles
• Rolling monthly contracts
• Budget providers using major UK networks

Prices and promotions can change frequently, so deals may vary depending on availability.

How we choose the cheapest SIM-only deals

To highlight low-cost SIM-only deals, we compare tariffs from UK mobile networks and approved retailers.

Deals are assessed based on:

• Monthly price
• Data allowance
• Contract length
• Network provider
• Any known price rises during the contract
• Features such as EU roaming or speed caps

This helps identify SIM-only deals that offer competitive pricing while still providing reliable mobile service.

Compare cheap SIM-only deals by network

Cheap SIM-only deals are available across all four major UK mobile networks:

• EE
• O2
• Vodafone
• Three

Many low-cost providers operate as mobile virtual network operators (MVNOs). These companies use the infrastructure of the major networks but sell their own SIM plans.

Examples include:

• giffgaff
• SMARTY
• Lebara
• Voxi

These providers often offer lower prices because they operate with fewer overheads.

Looking for the most affordable SIM-only deals? There are plenty of SIM deals from budget-conscious networks, usually hovering around the £5 mark.

Check out the following networks:

• Asda Mobile
• iD Mobile
• giffgaff
• SMARTY
• Lebara

What’s more, these SIMs are usually 5G-ready at no extra cost.

What to look for in a cheap SIM-only deal

The lowest monthly price does not always mean the best value. Looking at a few key factors can help you choose a plan that suits your usage.

Data allowance

Think about how much mobile data you typically use each month.

As a guide:

• 1GB to 5GB suits light browsing or messaging
• 10GB to 30GB suits regular streaming and social media
• Unlimited data suits heavy use

Choosing the right allowance can help avoid paying extra for additional data.

Contract length

Cheap SIM-only deals are usually offered as either rolling or fixed contracts.

Rolling SIM-only plans:

• Renew every 30 days
• Can usually be cancelled at any time

Fixed contracts:

• Often last 12 months
• Sometimes offer lower monthly prices

Network coverage

Mobile signal strength varies depending on where you live and travel. Before choosing a deal, it can help to check the provider’s coverage in your area.

Most UK mobile providers use one of the four main networks: EE, O2, Vodafone or Three.

Speed limits

Some low-cost SIM-only tariffs apply data speed caps. This means mobile internet speeds are limited to a maximum set by the provider.

Speed caps may affect activities such as streaming video or downloading large files.

Price rises

Some mobile contracts increase in price during the contract term. This may be:

• A fixed annual increase
• A rise linked to inflation

Checking this before signing up can help you understand the full cost of the deal.

Are cheap SIM-only deals worth it?

Cheap SIM-only deals can offer good value if your phone still works well.

They may suit people who:

• Have finished paying for a handset
• Prefer buying phones outright
• Want a lower monthly mobile cost

Because the handset is not included, the monthly price is usually lower than a standard phone contract.

What is a cheap SIM only deal?

A cheap SIM-only deal is a contract that gets you an allowance of data, calls and texts for a low-monthly charge – typically between £5 to £10.

The difference from traditional pay-monthly phone deals is that with SIM-only deals, you don’t get a new phone. As you’re only paying for the SIM and its monthly allowances, you get a lot more flexibility.

While you can still sign up to a 12-month or 24-month SIM deal, there are plenty of monthly rolling options, too.

How do cheap SIMS work?

Cheap SIMS work the same as any other SIM. Once you’ve picked the right package of minutes, texts and data for your needs, the SIM card will be sent to you. You’ll just need to insert your new SIM card into your phone.

Which networks offer cheap SIMS?

Plenty of networks, big and small, provide cheap SIM options. Here's a selection of networks that offer cheap SIMs and a glimpse of what they've got to offer:

• O2
• Vodafone
• Lebara
• VOXI
• iD Mobile
• giffgaff
• SMARTY

Cheap SIM-only deals from O2

Included with all O2 SIM-only deals, O2's Rewards scheme gets you discounts at high-street stores and restaurants. Plus, customers also get to be part of O2’s Priority scheme, which offers priority booking at O2 venues – great if you’re a music fan!

Cheap SIM-only deals from Vodafone

All Vodafone SIM-only customers can benefit from its VeryMe Rewards scheme. Incentives include discounts and freebies from a variety of high-street brands and retailers, as well as regular prize draws and competitions.

Cheap SIM-only deals from Lebara

One of the most budget-friendly networks out there, Lebara offers cheap SIMs with your choice of 100, 500 or unlimited international minutes to 42 countries. Customers can also get discounts on certain services, such as car insurance.

Cheap SIM-only deals from Lycamobile

Similar to Lebara, Lycamobile is another low-cost network that specialises in cheap SIMs with international minutes. It also offers eSims, which can be convenient if you often switch between SIM cards.

Cheap SIM-only deals from VOXI

If you’re a social butterfly, VOXI’s SIM plans allow you to spend unlimited time on social media including Facebook, Twitter, Snapchat and Instagram without using up your data allowance. Some plans even come with unlimited video streaming, so you can watch as much YouTube, TikTok and Netflix (among others) as you like, on the go.

Cheap SIM-only deals from iD Mobile

There’s plenty of choice with iD Mobile, as it offers a large variety of plan lengths and data allowances. SIM deals are available on one-month, 12-month and 24-month contracts.

If you sign up to a longer-term contract, some plans give you discounts for the first few months.

Cheap SIM-only deals from giffgaff

Giffgaff has a range of affordable and flexible plans – and if you’re willing to commit to a long-term contract, you get more bang for your buck.

As well as pay-as-you-go, no-contract deals (your plan lasts for one month, then it’s up to you to sign up to a new one), giffgaff offers monthly rolling plans (which you can cancel anytime) and 18-month contracts.

Cheap SIM-only deals from SMARTY

Another budget-friendly network, SMARTY has a small and straightforward selection of SIM-only deals. It also offers data-only plans – handy if you have a tablet or MiFi you want to use when you’re out and about.

What to look for in an affordable SIM plan

Using our mobile comparison table at the top of the page, you can check out all the SIM deals available.

From there, you can use the filters in the sidebar to narrow down the deals that fits your needs. You can sort by cost to find the cheapest ones, as well as set a maximum price, so you only see deals that are in your budget.

As well as cost, there are a few other things to consider when shopping around for a cheap SIM-only plan. Here are a few things to look out for:

Data allowance

When choosing a cheap SIM-only plan, you’ll need to consider the data allowance. In general, the cheaper the SIM, the lower the monthly data allowance.

So, if you use your phone to regularly browse the internet, online game, or stream video on the go, it’s worth paying a bit more to get the proper amount of data you’ll need. You could also consider looking into data-only SIMs you don’t need calls or texts, though we’d say they’re better suited to tablets or MiFi devices.

Unlimited social data

If you’re constantly Tweeting, uploading snaps to Instagram, or watching the latest TikTok trends, you should consider an unlimited social data plan. Some providers like VOXI and Virgin Mobile offer unlimited use of social apps and websites, such as Snapchat, WhatsApp, Facebook and Instagram, without eating your data.

Contract length

Typically, the longer your contract, the more you’ll get for your money. While SIM-only plans are great for their flexible monthly rolling deals, signing up to a longer-term contract can net you discounts on your monthly bill, or more data per month.

We can show you contract options of any length, from one month to 48 months – just use our comparison table above to compare.

Freebies

Cheap SIM-only deals can come with customer incentives and reward scheme memberships. These extras are usually only offered by the bigger networks, who may have higher prices than the smaller budget networks. But it’s still something to look out for when comparing deals, as you might find that the additional benefits are worth the higher SIM price.

For example, O2’s priority scheme gets you priority booking for gigs at O2 venues – if you’re an avid concert-goer, this is a great-to-have.

Pros and cons of cheap SIMS

If you’re not sure whether a cheap SIM deal is for you, check out our pros and cons list:

Pros

• You're less likely to end up paying for allowances you don't need or use
• Most 'value networks’ offer cheap SIM only deals
• Cheap SIMs often include many of the same customer incentives as pricier contracts

Cons

• You’ll need to have your own phone to use the SIM
• Depending on your phone use, you may find the data allowances restrictive
• The absolute cheapest SIM-only deals don’t come with extras or freebies

Alternative SIM-only plans

• Pay as you go SIM only deals
• 5G SIM only deals
• Unlimited data SIM only deals
• 30-day SIM only deals
• 12-month SIM only deals
• Bad credit SIM only deals

Our other useful guides

• Tips on avoiding roaming charges
• What to do if your phone is lost or stolen

Can I switch my SIM only deal with my existing network?

If you're on a 30-day rolling contract SIM only deal, you can switch to another deal with your network whenever you like. You'll just need to give 30 days' notice.

If you're on a 12-month or 18-month SIM-only contract, your network will almost certainly allow you to upgrade to a more expensive plan with bigger allowances. Some networks let you downgrade to a cheaper plan, though not all – it’s best to contact your network and explain your circumstances.

Of course, if you’re outside of the minimum length of your contract, you’re free to switch to whatever plan you like – even if it’s from the same network.

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

You won’t need to pass any credit checks if you’re getting a 30-day SIM. However, if you’re signing up to a longer-term SIM contract, you may need to pass a credit check before being accepted – usually if you’re getting a contract with one of the major networks (EE, O2, Three and Vodafone).

Nevertheless, some smaller companies don’t require you to pass a credit check, even if you’re signing up to a longer-term plan. This includes giffgaff’s 18-month contracts, as well as the likes of Lebara, Lycamobile and SMARTY.

Is it cheaper to get a SIM-only plan?

Yes, it’s almost always cheaper to buy a SIM-only plan than a pay monthly phone contract. That’s because with the SIM-only deal, you’re only paying your monthly allowances and not the cost of the new phone.

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

No, pay monthly is usually cheaper in terms of what you get for your money. With a SIM contract (both monthly rolling and long-term), you get a decent allowance of data, calls and texts. In comparison, pay-as-you-go deals (in which you top up your phone with credit) charges you for every MB of data, text and minute you use.

Pay-as-you-go is super flexible though, and you can easily adjust the way you use your phone to save money on your bill. And if you’re a very light user, you may find that topping up your phone with credit as and when needed works out cheaper than paying for a monthly plan.

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

Yes, you can keep your number. All you need is a PAC (porting authorisation code), and your network will handle the rest.

Using the ‘text-to-switch’ scheme, simply text ‘PAC’ to 65075. Your old network will promptly send you a PAC, which you can then give to your new network. They’ll then arrange for the switch to be completed within one working day.

Can I buy a SIM without a plan?

Yes – many networks let you order a free SIM without having to choose and pay for a plan upfront. Once you’ve received and activated it, you can then decide what plan you want, whether that’s a pay-as-you-go deal or a long-term contract.

If you want to buy a SIM with data, calls and texts, without committing to a long-term plan, you can easily do that with a 30-day SIM-only plan.