Best pay-as-you-go SIM deals in September

Best pay-as-you-go SIM deals this week

No time to trawl through thousands of pay-as-you-go (PAYG) SIMs for a good deal? Good news: we've done the hard work for you.You'll find our selection of the top pay-as-you-go SIMs on offer right now in the table above.

We've chosen them principally because we think they represent really good value for money. What’s more, they offer much more flexibility than a longer-term SIM deal or mobile phone contract.

What is a pay-as-you-go SIM?

A pay-as-you-go SIM is just another way of referring to a 30-day SIM. The term refers to a one-month contract which includes a monthly allowance of calls, texts and data.

Back in the day, ‘pay as you go’ used to mean having to pay a set amount for each text, call, or MB of data used. Once you run out of money on your plan, you simply ‘top up’ your SIM.

While you can still get these plans, 30-day SIMs are much more preferable in most cases. They’re better value, while still offering plenty of flexibility.

How does a PAYG SIM card work?

Here's how a 30-day PAYG SIM works. You sign up to a SIM, and it comes loaded with 30 days' worth of minutes, texts, and data ready to be activated and used.

The exact amount you get depends on the tariff you pick – you might get a set allowance of minutes and data, or unlimited use.

What’s more, you're only tied into this SIM deal for a single month. You can cancel it, change your allowance, or switch to an entirely different network whenever you like, penalty-free.

And if you’re happy with your plan, you can set it to automatically renew every month.

We recommend 30-day PAYG SIMs over traditional PAYG ones or longer-term SIM contracts, because they work out much cheaper without tying you down to a long contract.

And you can normally get one without a credit check.

Which networks offer pay as you go SIMs?

Plenty of networks offer PAYG SIMs, including:

• EE
• giffgaff
• iD Mobile
• O2
• Plusnet Mobile
• SMARTY
• Tesco Mobile
• Three
• Vodafone
• VOXI

Not sure which network to choose? To give you a helping hand, we've handpicked some of our favourite pay-as-you-go SIMs on each network.

We've also outlined their key selling points, so you can get a good idea of what you'll get for your money.

Three pay-as-you-go SIMs 

Three’s pay-as-you-go SIM plans are called ‘Data Packs’ and give you unlimited minutes, texts and ample amounts of data. And if you choose to auto-renew your plan, you get extra data every month.

Customers can also download the Three+ rewards app to enjoy exclusive offers from brands like Cineworld, Caffè Nero and Uber Eats, as well as access to pre-sale tickets to festivals.

Three has also been named as the UK’s fastest 5G network by one study, and all SIMs come 5G-ready, at no extra cost.

O2 pay-as-you-go SIMs 

O2 offers two types of PAYG SIM deals: ‘Big Bundles’ and ‘Rolling Plans’.

With Big Bundles, you top up every month, while Rolling Plans recur automatically. With both plans, you’re free to cancel or change whenever you want.

Depending on the plan you pick, you could get extras like EU roaming, international minutes, extra data for up to three months, or up to 10% of your payments back if you stick with O2 every month.

And all PAYG customers are part of the O2 Priority scheme, which gives you free gifts and exclusive access to gigs and perks.

Vodafone pay-as-you-go SIMs

Vodafone's 30-day pay-as-you-go bundles come with data rollover into the next month, as well as unlimited calls and texts.

What’s more, all PAYG customers can enjoy exclusive freebies and discounts via Vodafone’s VeryMe Rewards scheme. Whether it’s free coffees, discounted cinema tickets or exclusive deals with high street stores, there’s a great selection of rewards to be had.

iD Mobile pay-as-you-go SIMs

iD Mobile offers great value with its simple pay-as-you-go SIM plans.

All plans include unlimited minutes, texts, and a decent amount of data at a low price. What’s more, they come with inclusive EU roaming and no credit checks.

Don’t use your phone that much, or need extra data during your plan? You can also add top-up credit to your SIM and use that alongside your bundle, or even in lieu of a bundle.

SMARTY pay-as-you-go SIMs

SMARTY pay-as-you-go SIM-only deals are some of the most keenly priced around. As well as generous amounts of data, you get inclusive EU roaming and 5G at no extra cost.

If you have a tablet and don’t need calls or texts, you can also get a Data Only plan.

And if you want an extra SIM – whether that’s for a family member or an additional device – you can get it as part of a SMARTY Group Plan and save 10%.

giffgaff pay-as-you-go SIMs

Known as ‘goodybags’, giffgaff’s pay-as-you-go SIM plans are straightforward and well-priced.

As it’s powered by O2, giffgaff customers can make use of O2’s extensive public Wi-Fi hotspots – including on the London Underground.

And you can use your plan in the EU and selected destinations as you would back home, at no extra cost (though you’re subject to a 5GB roaming cap).

Pros and cons of PAYG SIMs

The good...

• Ultimate flexibility – no commitment to a contract
• Good way of keeping costs down if you're a light user
• No need to pass a credit check

The bad...

• You're more likely to run out of credit at inopportune moments (though you can usually set your plan to recur every month)
• You pay more for your allowances than you do on 12-month contract SIMs
• You normally miss out on the free gifts and perks that come with long-term contracts

What to look for in a PAYG SIM card

Not sure which pay-as-you-go SIM to choose? We've picked out some key criteria below:

Cheap pay-as-you-go SIM cards

The lowest-priced pay-as-you-go SIMs can be had for anything between £3-£6 a month. For that outlay, you can generally expect to get about 1GB of data per month, as well as unlimited calls and texts.

We'd recommend you to opt for a budget-friendly network, such as Asda Mobile, giffgaff,TalkMobile, iD Mobile, SMARTY and Lebara – all of which are great choices.

Pay-as-you-go SIM cards with freebies 

Networks are usually focused on keeping the costs down with pay-as-you-go SIM plans. As a result, you generally won’t get the same level of free gifts or value-adding sweeteners as you’d get by signing up to a long-term SIM contract.

Nevertheless, some household-name networks offer exclusive rewards schemes that PAYG customers can take advantage of. For example, Vodafone and O2 both operate customer rewards schemes that give you perks and discounts with high street brands, and even access to pre-sale gig tickets.

And plenty of smaller networks include useful features with their PAYG plans, such as data rollover and inclusive EU roaming.

What's the difference between traditional pay-as-you-go and 30-day PAYG SIMs?

Traditionally, the term 'pay as you go' meant buying phone credit to add to your SIM. You’d be charged a certain amount for every individual minute, text and MB of mobile data used.

With traditional PAYG, you only pay for what you use. While this may work out cheaper if you don’t use your phone much, you’ll pay higher rates than with a 30-day PAYG SIM contract.

With pay-as-you-go SIMs, you pay one price for a set allowance of calls, texts and data every month. For most mobile users, PAYG SIMs are much better value for money, and they still offer the same sort of flexibility as traditional pay-as-you-go.

What is the cheapest pay-as-you-go network?

Many UK mobile networks, from the big names to the smaller networks, offer pay-as-you-go SIM deals. But which one is the cheapest?

For cheap SIM-only deals, it’s worth looking at the smaller budget networks, such as Asda Mobile, Tesco Mobile, Lebara, Lyca Mobile, iD Mobile, SMARTY and giffgaff.

The cheapest and most basic PAYG plans usually start out at 1GB of data per month. We’d recommend Asda Mobile, SMARTY and Lebara as standout options, as their plans start from 3-4GB of data per month.

Some of the cheapest PAYG deals may have a set allowance on minutes and texts (for example, 150 minutes and 500 texts), but most include unlimited calls and texts as standard.

Overall, cheap PAYG SIM deals represent good value for money.

Pay-as-you-go SIMs with unlimited data

Many networks offer pay-as-you-go SIM plans with unlimited data. They’re the most expensive option, but it means you’ll never have to worry about going over your allowance.

And even if a network you like doesn’t have an unlimited data option, they’ll usually have plans offering 50GB or 100GB of data a month – which is more than enough for even the most data-hungry of users.

Are 4G pay-as-you-go SIMs cheaper than 5G?

No – the vast majority of networks don’t charge anything extra for a 5G-ready SIM.

Just make sure your phone is 5G-compatible, and you’re good to go.

Alternatives to pay as you go SIMs

• Unlimited data SIMs 
• 30-day SIM only deals 
• 5G SIM only deals

Can I get a data-only SIM?

Yes – some networks offer data-only SIM deals. As the name suggests, there are SIM deals that get you a monthly data allowance, but no calls or texts.

These come in handy if you often use a tablet when you’re out and about, or you have a mobile broadband device, such as a dongle or MiFi.

Do pay-as-you-go SIMs still exist?

Absolutely – 30-day pay-as-you-go SIMs are an affordable and convenient way of getting a bundle of minutes, texts and data without a contract.

Not all networks offer traditional pay-as-you-go plans, but there are still plenty of options out there for those who prefer to top up a SIM with credit.

Will I have to top up every month?

If you’re on a 30-day pay-as-you-go SIM plan, your plan will expire after a month. You’ll then have to pay for your plan again – unless you set it to recur automatically every month.

As these plans are flexible, you don’t have to top up every month if you don’t want to.

And if you’re on a traditional pay-as-you-go plan, you’ll only need to top up once your credit runs out.

How long does pay-as-you-go credit last?

That depends on your usage and how much your network charges for every minute, text and MB of data used.

With traditional pay-as-you-go credit, you add money to your SIM, and some of that balance is spent every time you make a call, send a text, or use mobile internet. When it runs out (or when you think it might run out soon), you can top it up.

Bear in mind, though, your pay-as-you-go SIM could be cut off if it isn’t used for a certain amount of time – see below for more.

Is there a pay-as-you-go SIM that doesn't expire?

If you have a traditional pay-as-you-go SIM, your credit won’t expire as long as your SIM is active.

For most networks, this means using your phone at least once every six months. So, to prevent your PAYG credit from expiring, you just need to make one chargeable call or text, or use some of your mobile data within that time period.

However, if you don’t use your SIM at all in that period, you’ll likely lose access to your remaining credit.

Different networks have different policies, so it’s best to check with your mobile network.

Can I get a SIM-only deal and keep my number?

Yes. Whether you go for a mobile contract or SIM-only deal, it’s easy to keep your number. Simply ask your current network for a PAC code and then send this code to your new network within 30 days.

If you're keeping the same mobile phone but changing networks, remember to check if your handset is locked to your old network. If it is, get in touch with them to unlock your device.

Read our guide on how to keep your mobile number when you switch networks.

Which UK networks offer traditional pay-as-you-go?

These days, traditional PAYG SIMs – in which you top up your SIM with credit to pay for every minute, text, and MB of data used – are not as popular.

They’re not as cost-effective as 30-day PAYG SIMs, but they may be a good option if you don’t use your phone regularly. If that’s what you’re after, your choices of network include:

• Asda Mobile
• Tesco Mobile
• iD Mobile
• giffgaff
• O2
• Three
• Vodafone

Some of them also let you use your credit to buy a 30-day PAYG plan with a set amount of calls, texts and data, if you decide you’d prefer that.

Are pay-as-you-go SIM cards free?

Yes, you can pick up a pay-as-you-go SIM from a shop or by ordering one online from your network of choice – usually for free, or for very cheap.

However, you'll need to top it up with credit or buy a 30-day PAYG plan before you can use it.