Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →This is a retrospective of offers effective in April 2026, not a live price list. The lowest clearly documented unlimited UK-data price was Three’s 24-month plan at £22 a month (£528 over the minimum term), subject to its preferred recurring-payment discount and a stated 100Mbps maximum. Three also listed £26 12-month and monthly-rolling options. Other networks may be better for roaming, local coverage, flexibility or premium speeds, while “unlimited” can still mean a speed cap, fair-use rule or traffic management.
Retail promotions change quickly. Check the linked tariff and coverage pages before ordering, and treat any price shown below as historical unless the provider confirms it is still available.
April 2026 unlimited SIM-only deals at a glance
| Provider | April 2026 price evidence | Contract | UK data and speed | Hotspot and router use | Roaming | Best suited to |
|---|---|---|---|---|---|---|
| Three | £22/month (24 months); £26/month (12 months or rolling) on the up-to-100Mbps tier. Premium “best possible network speeds” tiers were £39 (12 months) and £36 (24 months), subject to the guide’s tariff formatting. | 30-day, 12-month and 24-month options | Three describes UK data as truly unlimited; cheaper tier is up to 100Mbps. | Hotspot use is included for specified boosts; check the plan wording. A phone SIM is not automatically a supported home-router service. | Go Roam use up to 12GB; many customers joining or upgrading after 1 October 2021 pay a daily charge. | Lowest verified long-term price and heavy UK use |
| EE | Exact April prices must be taken from the dated guides effective 13 and 29 April; not stated in the available retail evidence. | 30-day and 24-month options advertised | Unlimited plans may be slowed at busy locations after 600GB in a month. | Check the individual plan and terms before sustained tethering or router use. | Allowance and any daily charge depend on the exact tariff and start date. | Readers who value EE coverage or bundled benefits |
| Vodafone | Indexed pages showed relevant staged prices of £26.50 and £25.80 from 1 April 2026; some premium options were about £44.80. Promotion, term and tariff must be confirmed. | Varies by plan | Unlimited data is sold in speed tiers; one relevant offer states a 100Mbps cap. | Check the plan’s tethering and acceptable-use terms. | Destination count and allowance vary by tier. | Users wanting Vodafone 5G and a particular speed tier |
| O2 | The page later displayed £22 Unlimited Mini and £28.99 Unlimited Ultimate, but that promotion ended 5 August and is not evidence of an April price. | Displayed offers were 24 months | Fair-use terms apply; “unlimited” does not remove device restrictions. | Standard unlimited SIM-only tariffs prohibit use in devices requiring a permanent mains connection, so they are unsuitable for many routers. | Up to 25GB in Europe on relevant plans; selected Plus or Ultimate benefits can include wider destinations. | Roaming benefits and O2 extras, where the tariff fits |
| iD Mobile | Flexible 30-day and longer plans are advertised; an April 2026 price was not established in the supplied primary evidence. | 30-day and longer terms | UK allowance is marketed as unlimited, subject to plan terms. | Check tethering conditions and acceptable-use rules. | Inclusive roaming is subject to a 30GB fair-use limit. | Lower-cost MVNO alternative |
Primary tariff pages: Three’s 19 April 2026 guide, EE’s archived guides, Vodafone offers, O2 SIM-only deals and iD Mobile unlimited plans.
What “unlimited data” actually means
Unlimited volume is not unlimited speed
A plan can remove a monthly gigabyte allowance while imposing a maximum speed. Three’s £22 and £26 April options were in the up-to-100Mbps tier. Vodafone also lists speed-tiered unlimited plans. A premium tier with the highest available network speed is a different product and should not be compared as though it were the same service.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
- WHAT YOU GET: Three (3) months of unlimited talk, text, and data delivered on the nation's largest 5G network. Data speeds may slow after 50GB when network is busy but data is unlimited. Videos stream at 480p.
- OH, YOU GET THIS TOO: 5G for Free + free mobile hotspot + Wi-Fi calling and text + free international calls to Mexico and Canada
- HOW YOU GET IT: The SIM Kit comes with a 3-in-1 SIM card that includes standard/micro/nano sizes, insert the SIM into your device, and activate on the Mint Mobile website or app. You can activate service on your own unlocked device with our Bring Your Own Phone (BYOP) program. Check your coverage and phone compatibility on the Mint Mobile website.
- WHO SHOULD GET IT: Anyone who hates their phone bill
- WHY YOU SHOULD GET IT: Mint Mobile took what’s wrong with wireless and made it right. We re-imagined the wireless shopping experience and made it easy and online.
Traffic management and fair use still matter
Three says its UK unlimited data is truly unlimited. EE says speeds may be slowed at busy locations after 600GB in a month, so its unlimited label does not guarantee unrestricted performance at every site. O2 applies fair-use and acceptable-use conditions. Read the tariff terms rather than relying on the word “unlimited”.
Roaming is a separate allowance
UK unlimited data normally becomes a fixed roaming allowance or a paid service abroad. Three’s Go Roam allowance is up to 12GB, O2 offers up to 25GB in Europe on relevant arrangements, and iD Mobile’s roaming fair-use limit is 30GB. Vodafone and EE allowances depend on the exact tariff.
Three: the clearest April 2026 price leader
Three’s Advanced Plans guide effective 19 April 2026 gives the strongest dated price evidence. On the up-to-100Mbps unlimited-minute tier:
- £22 a month for 24 months: £528 before any contractual increases.
- £26 a month for 12 months: £312 minimum-term cost.
- £26 monthly rolling: £26 for each month used, with no 12- or 24-month commitment.
The quoted prices include a £5 discount for Three’s preferred recurring-payment method, so the payment condition must be met. The rolling plan costs more over time but is easier to leave. Premium “best possible network speeds” options were listed at £39 for 12 months and £36 for 24 months; confirm the PDF table and current availability before relying on those figures.
Rank #2
- NO CONTRACT: Pay $5 - $25/month for a fully customizable phone plan - choose your talk, text, and data with no strings attached; upgrade, downgrade or cancel your plan anytime with no penalties
- UNIVERSAL SIM CARD INCLUDED: The kit contains one three-in-one SIM card (nano, micro, and standard sizes) to fit most unlocked GSM-compatible smartphones
- NATIONWIDE 5G COVERAGE: Stay connected coast to coast with nationwide coverage on America's largest 5G network
- INTERNATIONAL CALLS TO 60+ COUNTRIES: All Tello plans include international calling to over 60 countries
- EASY ACTIVATION: Bring your own phone and activate your SIM on the Tello website; check your phone compatibility and coverage maps before purchasing to confirm service in your area
Three describes UK use as truly unlimited, but Go Roam is capped at 12GB and can attract a daily charge for many customers. Coverage and congestion remain postcode-specific; use Three’s buying page and local coverage checker before committing.
EE: strong network proposition, but heavy users need the 600GB warning
EE retains archived price guides effective 13 and 29 April 2026, which are the appropriate source for exact historical monthly prices and annual-increase terms. The retail page advertises 30-day and 24-month SIM-only choices, but its current shop prices should not be backdated to April.
EE’s important limitation is operational rather than a stated gigabyte cut-off: the provider says an unlimited plan may be slowed at busy locations after 600GB in a month. That matters to extreme streamers, large downloads and sustained hotspot users. Roaming charges and allowances also vary by tariff start date, so check the archived guide and plan summary for the specific offer.
Vodafone: compare speed tiers and staged prices carefully
Vodafone’s indexed pages showed relevant April 2026 price signals of £26.50 and £25.80 from 1 April, with some premium unlimited options rising to about £44.80. These are staged or promotional figures, not a universal Vodafone price: term, plan name, promotional end date and annual increase can change the total cost.
Rank #3
- Includes two US Mobile SIM cards, one for the Warp Network and one for the Dark Star Network.
- Easy activation. Get started in minutes and manage your lines any time!
- 5G plans starting from $4/month
- Unlimited Premium plan with up to 10 GB International Data
- 24/7–365 world-class customer support. Get help from a real person within seconds
Vodafone promotes 5G at no extra cost, but 5G availability does not mean unlimited speed. One relevant Unlimited Plus offer states a 100Mbps cap. Compare the maximum speed, not just the data label, and confirm hotspot and roaming rules in the checkout summary. See Vodafone’s best SIM-only deals and its staged-price page.
O2: useful roaming benefits, with a major router restriction
O2’s later retail page displayed Unlimited Mini at £22 and Unlimited Ultimate at £28.99 on 24-month terms, with £2.50 increases each April from the relevant billing year. The promotion shown ended on 5 August, so these are not April 2026 prices.
O2 can suit travellers: relevant SIM-only plans include up to 25GB in Europe, while selected Plus or Ultimate benefits cover additional destinations. However, O2’s unlimited tariff terms prohibit using standard phone or SIM-only unlimited data in devices requiring a permanent mains connection. That makes an ordinary O2 unlimited phone SIM a poor choice for a dedicated 4G/5G router or permanent home-broadband replacement. Read the unlimited tariff terms before tethering heavily.
iD Mobile: a lower-cost MVNO option with a 30GB roaming ceiling
iD Mobile offers unlimited-data SIM-only plans on 30-day and longer contracts. Its UK allowance may be unlimited, but inclusive roaming is subject to a 30GB fair-use limit, so it is not “unlimited abroad”. The MVNO can be attractive when price and flexibility matter more than a direct network operator’s support or priority handling. Check the current offer at iD Mobile’s unlimited-data page.
Rank #4
- Cellular Service for Just $5: One of the lowest and most affordable subscription plans! Includes 100 talk minutes, 100 texts, and 100MB of ultra-fast data with your prepaid SIM card. No contracts!
- Easy Activation: A valid credit card is required for activation. No contracts, Cancel anytime. SpeedTalk Mobile offers its services through subscription plans. You can also call us for assistance 7 days a week with live technical support when you contact our toll-free number.
- Universal Compatibility: Bring your own phone and use any compatible device on the SpeedTalk Mobile network. The SIM card can be used to activate any unlocked 5G, 4G LTE, and VoLTE-compatible phone, including iPhones, Android devices (Samsung Galaxy, Google Pixel, LG), Windows phones, and non-smartphones. Our triple-cut SIM card is designed in three sizes (Mini/Micro/Nano) to ensure compatibility with a wide variety of devices. Simply punch out the size that fits your device and insert it.
- How does it work: The SIM Kit includes a 3-in-1 SIM card (standard, micro, and nano sim card) to fit all SIM Devices. Also it supports eSIM activation on Apple, Google, Samsung devices.
- eSIM: During activation, you can choose to use your physical SIM or switch to eSIM. The eSIM is available on iPhone 11 and newer models, Google Pixel 2 and higher, and compatible Samsung devices.
Which unlimited SIM is best for your use?
Lowest locked-in UK cost
Three’s £22 24-month plan is the lowest verified April 2026 price in the primary evidence: £528 over 24 months, before any contractual annual increases and subject to the recurring-payment discount. It is an up-to-100Mbps plan, not the premium highest-speed tier.
Best flexibility
Three’s £26 monthly-rolling option avoids a two-year commitment. Pay for the flexibility only if you may move, change networks or test coverage soon.
Best for premium speed
Compare Three’s premium “best possible network speeds” tier with any EE tariff whose April guide confirms no stated maximum speed. Do not assume a plan is uncapped merely because it says unlimited; verify the tariff’s speed and traffic-management wording.
Best for roaming
O2 may be preferable for regular European travel or selected wider roaming benefits, provided its fair-use and device rules fit. Three’s 12GB Go Roam allowance and potential daily charges are less attractive to frequent roamers. iD Mobile’s 30GB cap is generous for occasional trips but finite.
Free tools Windows power users keep installed
One-click scans. No signup required.
Best Value
- Includes 3-in-1 sized SIM cards (Nano, Micro, Standard), with options of a CDMA or GSM SIM for network selection and compatibility.
- SIM cards and service plans are compatible with both 4G LTE and 5G networks.
- Service plan sold separately required for active service.
- Powerful coverage on SIMPLE Mobile’s nationwide 5G network
- No contracts, no mystery fees.
Best budget alternative
iD Mobile is the clearest MVNO alternative when you want unlimited UK data and inclusive roaming, while accepting the 30GB overseas ceiling and MVNO-specific terms.
Hotspotting and replacing home broadband
Phone hotspot use
Check whether tethering is included, whether it has a separate allowance and whether roaming changes the rule. Three’s April guide expressly refers to hotspot use for some data boosts. Sustained high-volume tethering can still be subject to acceptable-use or traffic-management conditions.
Router compatibility
A phone SIM is not automatically a legal or practical broadband replacement. O2’s unlimited tariff explicitly excludes devices requiring a permanent mains connection. Other plans may permit tethering but not commercial resale or abnormal use. If the SIM will live in a router, choose a dedicated 4G/5G home-broadband product that explicitly supports router use.
When mobile data works at home
- One person or a small household has a strong indoor 4G/5G signal.
- Usage is light to moderate and not dependent on guaranteed latency.
- The plan permits the intended tethering or router setup.
Dedicated broadband is safer for several simultaneous users, weak indoor signal, competitive gaming, frequent video calls or a service that must remain stable when a mobile cell is congested.
Check coverage before switching
- Enter your home, workplace and regular commute postcodes in the provider’s current coverage checker.
- Compare indoor and outdoor predictions; thick walls can make a large difference.
- Confirm your phone supports the network’s relevant 4G and 5G bands.
- If uncertain, test a low-cost rolling SIM before taking a 12- or 24-month contract.
- Ask whether the address is served by the network’s own capacity or a changing shared arrangement.
No national network is automatically best everywhere. Building materials, local cell loading and handset compatibility can outweigh nationwide marketing claims.
Contract and price-rise checks
- Calculate the minimum-term total, not just the headline monthly figure.
- Record whether a direct-debit or recurring-payment discount is required.
- Check annual April increases and whether they apply during the entire term.
- Separate a promotional price from the post-promotion price.
- Check upfront fees, credit-check requirements and the cancellation process.
- Verify roaming charges, fair-use limits and hotspot rules for the destinations you visit.
- Save the tariff summary and terms on the day you order; retail pages can change or expire.
Sources and dated evidence
EE price-plan archive: https://ee.co.uk/help/terms-and-conditions/price-plans/mobile/sim-only-price-plans
EE retail and 600GB rule: https://ee.co.uk/mobile/sim-only-deals
Three April guide: https://www.three.co.uk/content/dam/threedigital/terms-and-conditions/price-guides/latest-price-guides/advancedplans-priceguide-post19apr2026-19042026.pdf
Three unlimited-data policy: https://www.three.co.uk/support/internet-and-apps/what-is-unlimited-data.html
Vodafone: https://www.vodafone.co.uk/sim-only/best-sim-only-deals and https://www.vodafone.co.uk/sim-only/cheap
O2 deals: https://www.o2.co.uk/shop/sim-cards/sim-only-deals
O2 terms: https://www.o2.co.uk/termsandconditions/mobile/unlimited-tariff-terms?q1=Top&view=html&x1=page_type
O2 tariffs: https://www.o2.co.uk/shop/all-tariffs
iD Mobile: https://www.idmobile.co.uk/sim-only-deals/unlimited-data-plan
The Bottom Line
Bottom line: For the lowest verified April 2026 cost, Three’s £22 24-month up-to-100Mbps plan leads at £528 before increases. Choose the £26 rolling version for flexibility, a premium tier for speed, O2 when roaming benefits outweigh its restrictions, and iD Mobile for a budget MVNO alternative. Check postcode coverage, router legality, speed caps, roaming limits and annual increases before signing.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
