Unlimited Data Plans on UK Mobile Networks: Best Unlimited Data SIM Cards

ASDA Mobile

On ASDA Mobile, it’s currently possible to get an unlimited data plan from £23 per month. This comes with access to Vodafone’s 5G network, with download speeds of up to 150Mbps.

ASDA Mobile’s unlimited data plans are shown in the following table:

Network	Data	Monthly Cost
Vodafone coverage Unlimited mins Unlimited texts	Unlimited data	£23.00 per month 24 month contract	See deal
Vodafone coverage Unlimited mins Unlimited texts	Unlimited data 150Mbps max speed	£24.00 per month 1 month rolling	See deal
Vodafone coverage Unlimited mins Unlimited texts	Unlimited data	£24.00 per month 12 month contract	See deal

If you choose a 12-month or 24-month Pay Monthly plan, you’ll get some of your monthly bill back in your Asda Rewards Cashpot. This will reduce the effective price of your plan.

In the past, some of ASDA’s unlimited data plans were sold with a download speed limit of either 2Mbps or 10Mbps. As of December 2024, these unlimited data plans have been withdrawn from sale. As such, all of their unlimited data plans now have download speeds of up to 150Mbps.

Source: ASDA Mobile Unlimited Data Plan
Tariff Information: ASDA Mobile Website

EE

On EE, you can get unlimited data from £23 per month (reduced to just £10 per month if you have an eligible EE home broadband plan). The download speeds and features available will depend on the type of plan you choose.

The cheapest way to get unlimited data on EE is to get one of their No Frills unlimited data plans from £27 per month. This will have a maximum download speed of 10Mbps (roughly equivalent to a basic 4G connection):

For download speeds of up to 100Mbps, and the ability to gift up to 100GB of spare data to another EE SIM card on your account, you can upgrade to an EE Essentials unlimited data plan from £23 per month:

Meanwhile, if you’re looking for uncapped download speeds and Inclusive Extras on your plan, choose one of EE’s All Rounder or Full Works SIM cards.

With All Rounder, you can choose to have one Inclusive Extra for the lifetime of your plan. Options include Apple Music, Netflix, the Roam Abroad Pass, TNT Sports on discovery+, the Xbox Game Pass Ultimate, or Microsoft 365 Personal. Depending on the option you choose, this Inclusive Extra is worth up to £25 per month.

EE’s Full Works plans come with three Inclusive Extras such as Apple Music, Apple TV+, Apple Arcade, TNT Sports Ultimate on discovery+, and the Roam Abroad Pass:

There are three key restrictions worth being aware on EE’s unlimited data plans:

1. There’s a fair usage limit of 600GB per month, above which EE reserves the right to “apply traffic management controls to deprioritise your mobile traffic during busy periods or to move you to a business plan”. For customers who signed up before the 1st September 2020, this fair usage limit was 1,000GB per month.
2. Tethering and personal hotspot usage is limited to a maximum of 12 devices.
3. You can use your allowances abroad in Europe for £2.47 per day (unless you have the Roam Abroad Pass, in which case roaming is included). A data roaming limit of 50GB per month applies when you travel abroad outside the UK.

If you’re using the Data Gifting feature on an EE Family account, you’ll be able to gift up to 100GB of data to other users on your plan (or 120GB if you’re on a 5G handset plan with unlimited data). The Data Gifting feature is not available on the No Frills plan.

For more information, read our EE unlimited data review.

Source: EE Website
Tariff Information: EE Website

giffgaff

In the UK, giffgaff offers 4G & 5G coverage from O2, with a choice of one-month rolling plans and 18-month contracts. There’s no credit check required on giffgaff.

For unlimited data without any speed restrictions, the best value option is giffgaff's £25 per month contract. This gives you unlimited UK data at 5G speeds, along with unlimited UK minutes and unlimited UK texts.

If you’re looking for more flexibility, there’s also a one-month rolling plan, though you’ll need to pay £35 per month for this.

Plan	Data	Monthly Cost
O2 coverage Unlimited mins Unlimited texts	Unlimited data	£25.00 per month 18 month contract	See deal
O2 coverage Unlimited mins Unlimited texts	Unlimited data	£35.00 per month 1 month rolling	See deal

On giffgaff’s unlimited data plans, there’s a fair use limit of 650GB per month. In addition, giffgaff says you shouldn’t tether your phone to more than 12 devices at the same time.

Always-On data

Another option is to get an Always-On data plan from giffgaff.

With Always-On data, you’ll get a full-speed data allowance that’s either 80GB or 100GB per month.

If the full-speed data allowance is used up, your download speeds will drop to a maximum of 384kbps between 8am and midnight each day (about 0.4Mbps). This is roughly equivalent to the speed of a basic 3G connection. It won’t stop you from browsing the internet or sending messages through WhatsApp. However, online video streaming is unlikely to work at this speed.

If you’re travelling abroad to another European country, you’ll be able to use up to 5GB of data at no extra cost each month. Beyond this, a surcharge of 10p/MB will be charged against your Pay As You Go balance.

For more information, see our guide to unlimited data on giffgaff.

Source: giffgaff Website
Tariff Information: giffgaff Website

Honest Mobile

If you’re looking for unlimited data on an “ethical mobile network”, Honest Mobile offers unlimited data plans from £22.50/month. According to Honest, they’ll remove twice the carbon footprint of your smartphone, making them a carbon negative mobile network.

Honest Mobile offers 4G & 5G coverage from Three on the following unlimited data plans:

Network	Data	Monthly Cost (will drop by 5% each year)
Three coverage Unlimited mins Unlimited texts	Unlimited data	£22.50 per month 12 month contract	See deal
Three coverage Unlimited mins Unlimited texts	Unlimited data	£25.00 per month 1 month rolling	See deal

In the UK, there’s a 650GB per month fair use limit, above which your service will be “limited to 3G speeds”. You’ll also get 5 days of inclusive EU roaming per trip (up to a maximum of 20GB data per month).

For more information, read our Honest Mobile review.

Source: Honest Mobile Plan Terms
Tariff Information: Honest Mobile Website

iD Mobile

iD Mobile is the own-brand mobile network from the Carphone Warehouse. They offer 4G & 5G coverage from Three.

At present, iD Mobile offers the following unlimited data plans from £15/month:

Network	Data	Monthly Cost
Three coverage Unlimited mins Unlimited texts	Unlimited data	£15.00 per month 1 month contract	See deal
Three coverage Unlimited mins Unlimited texts	Unlimited data	£15.00 per month 24 month contract	See deal
Three coverage Unlimited mins Unlimited texts	Unlimited data	£16.00 per month 12 month contract	See deal
Three coverage Unlimited mins Unlimited texts	Unlimited data	£17.00 per month 1 month contract	See deal

iD Mobile haven’t published a fair usage policy for their unlimited data plan, but their terms and conditions say the plan is for “personal use only”. You’ll need to undergo a credit check when you join the iD Mobile network.

Source: iD Mobile Terms and Conditions
Tariff Information: iD Mobile Website

Lebara Mobile

On Lebara Mobile, it’s currently possible to get unlimited 5G data for just £12.50 per month for 3 months (or just £11.25 per month when you sign up for 12 months).

The most popular and most flexible option is Lebara’s £25 unlimited data SIM. This comes on a one-month rolling basis, with no contract and no credit check required. You’ll also get unlimited UK minutes, unlimited UK texts, and 100 international minutes to 42 countries. As there’s no contract, you can change or cancel your plan at any time.

As an exclusive offer for our readers in May 2025, you can get 3 months half price when you order through this link, entering KEN3 as your voucher code at checkout. This will allow you to get the £25 unlimited data SIM for just £12.50 per month for 3 months.

Network	Data	Monthly Cost
Vodafone coverage Unlimited UK mins Unlimited UK texts 100 intl mins	Unlimited data	£12.50 for 3 months, then £25 per month 1 month rolling	See deal
Vodafone coverage Unlimited UK mins Unlimited UK texts Unlimited intl mins	Unlimited data	£15.00 for 3 months, then £30 per month 1 month rolling	See deal

For even bigger savings, you can sign up to Lebara on a 12-month plan. This will give you a further 10% off, bringing the price down to as little as £11.25 per month for 3 months (then £22.50 per month thereafter).

Network	Data	Monthly Cost
Vodafone coverage Unlimited UK mins Unlimited UK texts 100 intl mins	Unlimited data	£11.25 for 3 months, then £22.50 per month 12 month contract	See deal
Vodafone coverage Unlimited UK mins Unlimited UK texts Unlimited intl mins	Unlimited data	£13.50 for 3 months, then £27 per month 12 month contract	See deal

As before, you’ll need to enter KEN3 as your voucher code at checkout to get the 3 months half price.

According to Lebara Mobile, there are no usage caps on their unlimited data service, with exceptions for fraudulent usage and their general terms and conditions:

Where Unlimited data is included in a plan allowance, there is no data cap, subject to fraud exceptions. All general T&C will apply.

If you’re using your Lebara Mobile SIM card abroad in Europe or India, you can use up to 30GB data per month at no extra cost. If you use the entire 30GB allowance, you can choose to renew your plan early to get a fresh 30GB allowance. Alternatively, you can buy a 5GB roaming bolt-on for £10.

For more information, see our Lebara Mobile unlimited data review.

Source: Lebara Mobile Terms and Conditions
Tariff Information: Lebara Mobile Website

Lyca Mobile

On Lyca Mobile, it’s currently possible to get unlimited data from £9/month for 6 months,
then £18 per month. You’ll also get unlimited UK minutes, unlimited UK texts and 100 international minutes included on your plan every month.

Network	Data	Monthly Cost
EE coverage Unlimited UK mins Unlimited UK texts 100 intl mins	Unlimited data	£9.00 for 6 months, then £18 per month 24 month contract	See deal
EE coverage Unlimited UK mins Unlimited UK texts 100 intl mins	Unlimited data	£11.00 for 3 months, then £22 per month 12 month contract	See deal
EE coverage Unlimited UK mins Unlimited UK texts Unlimited intl mins	Unlimited data	£12.50 for 6 months, then £25 per month 24 month contract	See deal
EE coverage Unlimited UK mins Unlimited UK texts 100 intl mins Offer ends 31st May	Unlimited data	£12.50 for 1 month, then £25 per month 1 month rolling	See deal
EE coverage Unlimited UK mins Unlimited UK texts Unlimited intl mins	Unlimited data	£13.50 for 3 months, then £27 per month 12 month contract	See deal

There’s a fair use limit of 450GB per month in the UK, above which the speed of your service will reduce to 128Kbps. You can use up to 35GB data per month at no extra cost when you’re travelling abroad in the EU. You’ll get access to 4G & 5G coverage from EE.

For more information, see our guide to unlimited data on Lyca Mobile.

Source: Lyca Mobile Website
Tariff Information: Lyca Mobile Website

O2

O2 offers unlimited data on a range of Pay Monthly SIM cards and handsets.

At present, you can get an O2 unlimited data SIM card from £25/month, with the lowest prices being available when you choose a 24-month plan:

You’ll get up to 3 months Apple Music included, along with 3 months of a different O2 Extra of your choice (such as Disney+, Amazon Prime Video, or Amazon Music). Meanwhile, if you upgrade to a more expensive ‘Unlimited Plus’ plan, you’ll get up to 6 months of Apple Music included, along with 6 months of another O2 Extra.

On O2’s unlimited data plan, there are several fair usage limits worth being aware of. The most important is their 650GB per month fair usage limit. In addition, the use of tethering and personal hotspot is limited to a maximum of 12 devices. If you exceed these limits twice in any six-month period, O2 says they “reserve the right to transfer you to a more suitable plan”.

O2’s terms and conditions also require you to use their unlimited data SIM card inside a battery-powered mobile device. This is intended to prevent you from using the SIM card for 4G home broadband or 5G home broadband:

3.3 Unlimited UK Data sold on handset or SIMO contracts must only be used in mobile devices that do not require to be plugged in order to work. Any O2 mobile broadband Unlimited UK Data tariffs must only be used with the devices that they are sold with. Where other devices are used that do not comply with these terms, we reserve the right to transfer you to a more suitable plan.

If you’re travelling abroad to another European country, you can use up to 25GB of data abroad in O2 Europe Zone countries. In addition, if you’re a Virgin Media customer or if you choose an Unlimited Plus plan, you’ll be able to use your SIM card abroad in a further 27 O2 Travel Inclusive Zone countries at no extra cost (this is subject to speed restrictions after the first 150MB of general data usage each day, or after the first 50MB of streaming data usage each day).

For more information, read our guide to O2’s unlimited data plans.

Source: O2 Website: Unlimited Plan Terms
Tariff Information: O2 Website

Sky Mobile

On Sky Mobile, it’s currently possible to get an unlimited data plan for £29 per month. This will give you access to O2’s 4G and 5G network.

Network	Data	Monthly Cost
O2 coverage Unlimited mins Unlimited texts	Unlimited data	£29.00 per month 12 month contract	See deal

According to Sky, their unlimited data plan is for “personal use only”. Their terms and conditions state that your usage of the plan “should not exceed that reasonably expected of a reasonable person using the Sky Mobile services for personal purposes as a consumer”.

The data rollover feature (Sky Piggybank) is not available on Sky Mobile’s unlimited data plan.

Source: Sky Mobile Terms and Conditions
Tariff Information: Sky Mobile Website

SMARTY

SMARTY is a low cost sub-brand of Three. They currently offer unlimited data for £16 on a one-month rolling basis (this is a special offer that’s running in May 2025).

On SMARTY, you’ll get unlimited minutes, unlimited texts and unlimited 5G data. You can also use the unlimited data SIM card in other devices like your tablet, dongle or mobile broadband router.

According to SMARTY, tethering and personal hotspot usage is included in the plan and there are no speed restrictions for using too much data. There is, however, a fair use limit of 12GB per month when you’re using your SMARTY SIM card abroad in Europe.

SMARTY offers 99% population coverage, using 4G and 5G coverage from Three.

Network	Data	Monthly Cost
Three coverage Unlimited mins Unlimited texts	Unlimited data	£16.00 per month 1 month rolling	See deal

Although it’s a one-month rolling plan, you’re able to benefit from the reduced price for up to 15 months.

The following table shows a summary of the key things to know about unlimited data on SMARTY:

For more information, see our SMARTY unlimited data review.

Source: SMARTY Website: Unlimited Plan
Tariff Information: SMARTY Website

Talkmobile

Talkmobile is a low-cost sub-brand of Vodafone. As a special offer, they’re currently offering unlimited 5G data for just £16 per month on a one-month rolling basis. You’ll get access to Vodafone’s 5G network with their fastest available speeds.

Network	Data	Monthly Cost
Vodafone coverage Unlimited mins Unlimited texts	Unlimited data	£16.00 per month 1 month contract	See deal

According to their terms and conditions, Talkmobile says the plan “is for personal use only and cannot be used for commercial or business purposes”. However, beyond that, there are no hidden limits on how much data you can use.

Source: Talkmobile: Terms and Conditions
Tariff Information: Talkmobile SIM Only Deals

Tesco Mobile

On Tesco Mobile, it’s currently possible to get an unlimited data SIM card from £25/month. This comes with access to 4G & 5G coverage on the O2 network.

The following table shows Tesco Mobile’s unlimited data SIM cards:

Network	Data	Monthly Cost
O2 coverage Unlimited mins Unlimited texts	Unlimited data	£25.00 per month 24 month contract Monthly cost rising to £26.50 on 1 Apr 2026	See deal
O2 coverage Unlimited mins Unlimited texts	Unlimited data	£30.00 per month 12 month contract Monthly cost will rise each April by CPI inflation plus 3.9%	See deal

Tesco hasn’t set a fair usage limit for their unlimited data plan. Instead, their terms and conditions simply state that you’re unable to use the service for commercial purposes, or for usage that adversely impacts other customers on Tesco Mobile.

Tesco says on their website that you can use the unlimited data SIM card for personal use in mobile devices, but not in 4G home broadband routers.

For more information, see our guide to Tesco Mobile unlimited data plans.

Source: Tesco Mobile Terms and Conditions
Tariff Information: Tesco Mobile Website

Three

On Three, you can get “truly unlimited data” from £20 per month when you order through this link.

There are no fair usage limits for unlimited data inside the UK. You’ll also get 5G coverage with no speed restrictions. However, commercial usage of the service is not permitted:

Use of our services for commercial, resale or fraudulent purposes isn’t allowed under our Terms for Three Services, so we do reserve the right to monitor any unusual activity that may indicate that this is happening to identify and prevent such non-permitted use.

The following table shows the best SIM-only plans from Three with unlimited data:

The cheapest way to get unlimited data on Three is through their £20 unlimited data SIM card deal. This is available exclusively when you order through this link. It’s a hidden deal so you won’t find it if you look directly on Three’s website.

Most customers choose one of Three’s Lite plans as this will give you unlimited data for the lowest possible price. For an extra £5 per month, you can upgrade to an Unlimited Value plan which gives you Paramount+ for the first half of your plan, and 14 daily Go Roam passes each year. The Unlimited Complete plan costs £10 per month extra. It comes with Paramount+ for the entire duration of your plan, plus 28 daily Go Roam passes per year.

As well as getting an unlimited data SIM card, you can also buy a smartphone from Three with unlimited data on a contract. Three also offers unlimited 4G home broadband and unlimited 5G home broadband.

Prior to September 2019, Three had a fair usage policy of 1,000GB per month (1TB) on their unlimited data plans. They’ve confirmed that this fair usage policy no longer applies on their plans:

If you have Unlimited Data as part of your package or with an Add-on, there are no hidden caps or limits when using your device within the UK. Unlimited Data lets you use the internet to your heart’s content, without worrying about hefty bills.

Use of our services for commercial, resale or fraudulent purposes isn’t allowed under our Terms for Three Services, so we do reserve the right to monitor any unusual activity that may indicate that this is happening to identify and prevent such non-permitted use.

For more information, see our guide to unlimited data on Three.

Source: Three Help: What is unlimited data?
Tariff Information: Three Website

Vodafone

Vodafone offers a selection of unlimited data plans from £30/month. This gives you access to both their 4G & 5G networks.

When you choose a Vodafone unlimited data plan, you’ll need to decide between three different speeds:

• Unlimited plans give you download speeds of up to 10Mbps.
• Unlimited Plus plans give you download speeds of up to 100Mbps.
• Unlimited Max plans have uncapped download speeds.

In the past, Vodafone has also sold Unlimited Lite plans with a maximum download speed of 2Mbps.

There’s no fair usage policy on Vodafone’s unlimited data allowance, except that it needs to be “for your personal and non-commercial use”.

Network	Data	Monthly Cost (rising to £31.80 on 1 Apr 2026 £33.60 on 1 Apr 2027)
Unlimited mins Unlimited texts	Unlimited data 100Mbps max speed	£30.00 per month 24 month contract	See deal

If you choose a Euro Roam or Global Roam plan, you’ll be able to use up to 25GB data per month when travelling abroad as part of Vodafone Global Roaming.

For more information, read our Vodafone unlimited data review.

Source: Vodafone Website
Tariff Information: Vodafone Website

VOXI

VOXI is the youth-orientated sub-brand of Vodafone. At present, they’re offering unlimited 5G data for £30/month, with no contract and no need for a credit check.

On VOXI’s unlimited data plan, you’ll get access to 5G coverage from Vodafone. You’ll also get unlimited UK minutes and unlimited UK texts.

Network	Data	Monthly Cost
Vodafone coverage Unlimited mins Unlimited texts Offer ends 29th May	Unlimited data	£30.00 per month 1 month rolling	See deal

According to their terms and conditions, VOXI says they “reserve the right to suspend or throttle the service if we have reason to believe that the SIM card is being used for commercial purposes, fraudulently or is having an adverse impact / damaging our network in any way”.

Source: VOXI: Terms and Conditions
Tariff Information: VOXI Website