Three SIM-only deals

Which Three SIM-only deal should you choose?

Start with the data you actually use, then check the contract term and features that could justify paying more. A direct Three plan may suit you if you value Three's own account services, Three+ rewards or a particular Go Roam benefit. If all you need is access to the underlying network, a different provider might cost less or offer a shorter commitment.

For a Three-branded SIM, begin with the live cards above. Use Full plan details to narrow your choice, then View Deal to confirm the selected offer at the provider's checkout. If Three reception is the priority rather than Three as the provider, compare the network alternatives separately instead of assuming the branded tariff will be your cheapest option.

What changes between Three Lite, Lite+, Value and Complete?

Three's Three Your Way tiers differ in more than price. The published standard plan characteristics reviewed in October 2026 are a useful guide, but the benefits of the actual offer matter most — some Lite promotions include an extra Full Speed Add-on.

Important exception: an eligible Lite with Full Speed Add-on offer can provide access to higher network speeds than standard Lite's 100Mbps ceiling. The add-on must actually be included or purchased on the selected offer. Do not determine its speed from the tier name alone. The Full Speed Add-on's availability and inclusion can differ across sales channels. Check the selected product's speed wording in the official Three Your Way information and its applicable price guide.

An unlimited UK data allowance is not the same as unlimited speed. Complete is not automatically faster than Lite+, despite its broader roaming benefits. Nor is a speed without a fixed cap a promise of a particular download result: signal, congestion, the phone and the location still matter. If your normal browsing and streaming work comfortably at an everyday speed cap, paying more for Full Speed may bring little practical benefit.

How much will a Three contract really cost?

A cheap first payment is not necessarily a cheap agreement. Compare the introductory months, subsequent charges, annual increases and how long you must stay. Contract totals shown in a card are useful, but a calculation based only on today's monthly price may differ from the bills due after scheduled increases.

Introductory price versus the real average

Consider a hypothetical 24-month agreement charging £10 for the first six payments and £20 for the next 18, with no upfront fee. Before annual increases, six payments cost £60 and the remaining 18 cost £360: £420 in total, or £17.50 per month on average. The advertised £10 opening price is not the cost you should compare against another 24-month plan. This is an illustrative calculation, not a currently advertised Three deal.

April increases on applicable newer agreements

Three's published terms effective 19 April 2026 specify the following fixed increases to the recurring monthly charge on covered consumer agreements, taking effect on applicable 1 April dates:

Older contracts, separate charges and different products can follow different rules. Check the date and type of the agreement you are buying; the figures above are a dated policy snapshot, not a guarantee for future contracts. Three's official 19 April 2026 network terms set out the applicable conditions.

For scale, take a second hypothetical example: a qualifying 100GB+ plan begins at £20 a month, with six payments before April 2027, 12 between April 2027 and March 2028, and six from April 2028. Assuming the stated £2.30 increase applies at each April and there is no promotion or other fee:

The simple £20 × 24 figure is £480, £55.20 lower. A different activation date, plan, discount or policy would change the calculation. If a DealPriceCheck card already includes scheduled increases in its minimum-contract or effective-monthly estimate, do not add those increases a second time. Use this example to understand the payment schedule, then check which charges the card's estimate actually covers and read the written terms at checkout.

Is 30-day flexibility worth it?

A rolling plan can be attractive if you are testing reception or may leave soon, even when its starting payment is higher. A 12- or 24-month plan may make more sense when you expect to stay and the entire commitment is competitive. Be careful not to confuse 30-day pay-monthly SIM-only with a separate Pay As You Go data pack: they can have different renewal, speed, cancellation and roaming terms. The live Three selection may not show every commitment Three sells, so an absence of short offers here is not proof that Three only sells long contracts. If no suitable short Three agreement appears in the cards, compare 30-day SIM-only deals across providers; do not confuse a rolling SIM with a PAYG Data Pack.

Is Three's unlimited 5G data suitable for your phone or hotspot?

Three markets unlimited UK mobile data on eligible phone plans and allows personal hotspot use within its service rules. That can be useful if you stream heavily, work through a laptop or rely on mobile data when Wi-Fi is unavailable. However, a domestic unlimited allowance does not override a plan-level maximum speed or guarantee reliable reception indoors.

Before choosing an expensive allowance, check recent use in your existing provider's app. Then use Three's coverage checker at home, work and the places where you actually need mobile data. Coverage forecasts are not a guarantee inside every building or on every train. If reception is uncertain, testing a suitable flexible plan before making a long commitment is a sensible precaution.

A 5G-capable phone and suitable plan are both needed for 5G service where coverage exists. Older handsets may also need compatible 4G voice calling because Three has switched off its 3G network. If you need an eSIM, Wi-Fi Calling or a particular watch or tablet feature, check the exact device and Three product rather than inferring support from a general 5G label.

Does Three include roaming, and how much data works abroad?

Go Roam is not a single promise attached to every Three SIM. It covers different destination bands, and inclusion depends on plan tier, customer terms and travel destination. On eligible newer Three Your Way offers, Value and Complete can provide inclusive Go Roam access or allocated passes, covering different destination bands. Do not assume that a Value or Complete label alone guarantees unlimited free roaming days. On Lite, a Go Roam pass or daily charge will usually be needed; contract start dates and special offers can change the entitlement.

For most eligible Go Roam destinations, Three publishes a 12GB per month roaming fair-use limit: you can use up to 12GB from your existing UK allowance, not 12GB on top of it. The Republic of Ireland is an important exception: Three says the usual 12GB fair-use limit and daily roaming charge do not apply there. That does not create an extra data allowance or remove your plan's underlying UK allowance. Hotspot eligibility and overseas usage restrictions can also vary by product and destination.

Before travelling, check three things against your exact plan: whether the destination is included, whether access is included or chargeable, and how much data and hotspot use you can actually take abroad. A cheaper Lite plan may be the more expensive choice for frequent travellers once passes are counted; conversely, paying for Complete purely for roaming is poor value if you rarely leave the UK. See Three's official Go Roam guidance for destination-specific conditions.

Three versus SMARTY and iD Mobile: which is better value?

Three, SMARTY and iD Mobile are different service providers, even though SMARTY and iD use Three's underlying mobile network. The Three-branded route is worth comparing when you want a particular Three Your Way benefit, Three+ or an offer directly from Three. SMARTY is relevant if rolling prepaid flexibility matters; iD Mobile offers its own mix of rolling and longer terms, eSIM and roaming conditions. A shared network is not a guarantee of identical speeds, coverage experience, customer support or features.

The practical test is to compare enough data, the same intended period and the features you will use. A rolling alternative is not automatically cheaper than a Three deal over 24 months; compare actual payments and any future rises over the period you expect to stay. Start with our Three-network SIM comparison for the selected network-based offers, or inspect SMARTY plans and iD Mobile deals separately. These are not substitutes for Three if its particular branded benefits are your priority.

The Vodafone–Three merger also needs context: network integration is progressing, but a listing marked Vodafone + Three is not proof that every Three, Vodafone or virtual-provider customer gets identical access. Choose on your actual plan and local coverage, rather than assuming the two brands have become interchangeable.

If your top priority is to lower your monthly bill and you are willing to use a different physical network, compare UK SIM-only deals and use the network filter. Our catalogue also includes EE-based providers such as 1pMobile and Lyca Mobile, which may offer relevant partner deals; those are not Three-network replacements and should be considered only when their coverage works for you.

Switching to Three: three practical questions

Can I keep my mobile number?

Usually, yes. Text PAC to 65075 from the number you want to retain and give the code to your new provider. Do not manually cancel the old line before the port; check any early-termination charge first. Our number-switching guide explains the process.

Does unlimited Three data mean unrestricted roaming?

No. UK unlimited data and overseas usage are separate. Three's Go Roam zones, pass eligibility, 12GB fair-use rule and destination-specific exceptions must be checked on the tariff you buy.

Should I choose Three or another provider using Three's network?

Choose Three if a specific Three offer or benefit earns its overall cost. Choose from the wider Three-network comparison if price, flexibility or a different provider's conditions matter more. Compare coverage, speed rules, minimum commitment and roaming side by side before selecting View Deal.

DealPriceCheck compares selected offers rather than the entire UK market. Price, promotions, eligibility and terms may change after each card's stated check date; verify the chosen deal at provider checkout. Some links can earn DealPriceCheck a commission at no extra cost to you.