SMARTY SIM Only Deals Explained: Plans, Pricing and What You Get

Roaming beyond SMARTY's EU list costs extra: 10p per MB for data in the US and £1 per MB in Japan. For trips like those, you can add a travel eSIM alongside your SMARTY SIM on a dual-SIM phone, and HelloRoam has plans for 185+ destinations.

Quick answer: top SMARTY SIM only deals at a glance

SMARTY sells two ranges. Rolling Monthly plans come with unlimited UK calls and texts as standard, while Data Only plans are sold as "just great value data". The table shows the Rolling Monthly prices from SMARTY's SIM only page, plus how much data each plan can use in the EU.

SMARTY runs on Three's network. You can join with a free physical SIM or an eSIM, so there's no waiting around for a card in the post if your phone supports eSIM.

No annual price rises. No credit check on any plan. Cancel any time.

The 100GB plan at £12 is where the value jumps. The 40GB plan costs £10, so the extra 60GB costs just £2 a month.

A SIM only deal covers the plan, not the phone

A SIM only deal gives you mobile data, calls, and texts without bundling in a handset. You bring your existing phone; the plan covers the connectivity. That's it.

A 24-month handset contract works differently. It bundles device repayments with the airtime, so the phone's price sits inside every monthly payment. A SIM only deal strips that out, leaving a lower monthly cost with no hardware to pay off.

Terms vary a lot. SMARTY's own FAQ notes that SIM contracts typically last from 30 days to 24 months. Longer contracts tie you in, while one-month rolling plans let you leave at the end of any month. The sensible choice depends on how stable your circumstances are.

SMARTY's SIM only plans all run on 1 month rolling terms, with no minimum term and the freedom to cancel at any time. To leave, you switch off auto-renew, and the plan ends at the end of your current billing month. SMARTY's guide to leaving covers the steps, including a PAC code if you want to keep your number.

SMARTY SIM only plans: pricing and what is included

Alongside the eight Rolling Monthly plans above, the same page lists five Data Only plans, from 2GB for £5 to unlimited data for £20.

Both ranges run month to month, and SMARTY lets you stop, start or change your plan as your needs change.

Every Rolling Monthly plan includes unlimited UK calls and texts. Tethering (sharing your phone's data connection with other devices) is allowed on every plan, with your full allowance. According to SMARTY's 5G page, all its SIMs get 5G at no extra cost, whatever the plan size, as long as your phone supports 5G. Run out mid-month and data add-ons cost £1 per GB, and they never expire while your plan is live.

EU roaming is included on SMARTY plans at no extra cost, but on plans over 12GB only 12GB of data a plan month works in the EU, under the fair use limit in SMARTY's roaming help.

That 12GB limit is the detail to know before a long trip. On the 100GB plan, you can use 12GB of it in Spain or Italy each plan month, unless you buy SMARTY's 1-day or 3-day EU Roaming pass, which lets you use your full unused UK allowance for that time. The limit doesn't apply in the Republic of Ireland. Data Only plans don't include calls and texts in the EU.

SMARTY's edge: no price rises and no credit check

SMARTY's pitch rests on three things: no annual price rises, no credit check, and a free SIM or an eSIM when you join. An earlier version of this guide also listed a data discount. That was out of date: SMARTY no longer sells data discount plans.

The data discount turned unused data on SMARTY's small 1GB, 2GB and 3GB plans into money off the next bill. SMARTY's help centre now says those plans are discontinued, and the discount isn't available on Rolling Monthly or Data Only plans. Customers already on a data discount plan can stay on it as long as they don't change plan.

No credit check sounds like a minor detail. It isn't if you're new to the UK or have a thin credit file. SMARTY's no credit check page says every SMARTY plan is available without one, because you pay for each month up front.

Mid-contract price rises have become a real irritant. Since April 2024, EE has set its annual rises in pounds and pence, applied each 31 March during a plan's minimum term. SMARTY advertises no annual price rises, and SMARTY's contact page explains why: its 1 month rolling plans can be cancelled at any time, so customers are never forced to accept a price increase part way through a contract.

eSIM support doesn't mean giving up a physical SIM. SMARTY offers both: new customers can get an eSIM straight away, and existing customers can switch to one in the app by ordering a replacement SIM. SMARTY's eSIM page says activation can take up to 2 hours, though it is usually quicker. Check your handset first against our list of eSIM-supported phones.

SMARTY SIM only deals and international travel: what to know

EU roaming is included on SMARTY plans, so you can use your allowance across SMARTY's EU list without the day charges some networks add. The list is not the whole of Europe: SMARTY's Europe roaming page includes Norway, Iceland and Gibraltar, but not Switzerland, Turkey or Montenegro. Outside it, including the US, Canada, Thailand and Australia, no SMARTY plan includes roaming.

Both the physical nano-SIM and the eSIM option work identically for EU travel. Whichever format you set up at home performs the same way in Madrid or Milan.

Here's the scenario that catches travellers out.

You book a summer trip starting in Croatia, then extend it to Montenegro for a few days. Croatia is on SMARTY's EU list; Montenegro is not. The moment your phone connects to a Montenegrin network, data, calls and texts only work if you've bought 'Out of plan' add-ons, and data costs 10p per MB there, SMARTY's Montenegro page shows. Turkey works the same way: partly in Europe, outside SMARTY's list, and charged at 10p per MB.

Post-Brexit, this distinction carries real weight. Before 2021, UK customers roamed across the EU under shared rules. The UK government now says surcharge-free roaming in the EU is no longer guaranteed, and some networks charge for it: EE's roaming page lists £2.72 a day to use UK allowances in the EU. SMARTY's inclusion covers its EU list, not the wider continent. For a trip that crosses into non-EU countries, our eSIM guide for Europe covers the options.

Non-EU long-haul is where the costs bite.

Outside SMARTY's EU list, data, calls and texts work only with 'Out of plan' add-ons, charged as you use them. SMARTY's own rate pages put data at 10p per MB in the US, roughly £100 for 1GB, and £1 per MB in Japan. SMARTY also sets a £45 worldwide data roaming limit on your account by default. Once you reach it, outbound calls, texts and data stop until the limit resets, unless you've asked SMARTY to change it. In Japan, £45 buys about 45MB. Our data roaming guide for UK travellers shows how these charges build up.

When a travel eSIM makes sense alongside SMARTY

Long-haul travel shifts the calculation. SMARTY includes no roaming outside its EU list, so in the US, Japan or Thailand every megabyte comes from paid add-ons. A travel eSIM works the other way round: you buy a set amount of data for your destination before you fly, and it connects to a local network when you land.

HelloRoam connects to 212+ networks worldwide. For a Tokyo trip, for example, you can buy one of our Japan eSIM plans before you leave and keep SMARTY for your UK number. Our eSIM versus SIM card comparison covers the wider trade-offs for UK travellers.

Apple's Dual SIM guide says the iPhone XS, XS Max, XR and later can use a physical SIM and an eSIM together, with separate lines for calls and data, and iPhone 13 and later can also use two eSIMs; our guide to eSIMs on iPhone walks through the setup. Apple adds that your iPhone must be unlocked to use plans from two different networks. Keep your SMARTY SIM in the tray for your UK number, or use a SMARTY eSIM on an eSIM-only model like iPhone Air, and set the travel eSIM as your data line. Outside the EU, SMARTY says calls and texts won't work without 'Out of plan' add-ons, so add a little credit before you fly. Receiving texts is free in the US and Japan; receiving calls costs 5p a minute in the US and £1 a minute in Japan.

For a long weekend in Lisbon, SMARTY's EU roaming covers you. A fortnight in Japan or two weeks on the US East Coast is a different matter, as the per-MB rates above show.

SMARTY's strengths and weak spots

SMARTY is a good pick if you want cheap SIM only deals without a contract: 100GB costs £12 a month, every plan is 1 month rolling, and there is no credit check and no annual price rise.

Monthly plans are cancellable without penalty: switch off auto-renew and the plan ends with your billing month. Extra data is £1 per GB, so one heavy month doesn't force you onto a bigger plan.

Support is the honest downside. SMARTY is digital-first, with web chat instead of a general phone line. For most users managing a standard plan, that's not a problem.

SMARTY suits budget-conscious users, anyone who values monthly flexibility, and eSIM adopters who want a low-cost UK number without a long commitment.

Less suitable for: frequent travellers outside the EU. Beyond SMARTY's EU list, every megabyte is charged, and no SMARTY plan changes that.

SMARTY's network: Three, plus shared Vodafone sites

SMARTY runs on Three's network. SMARTY's help centre puts it plainly: Three owns SMARTY, and the two share the same network. Three UK and Vodafone UK merged on 2 June 2025, and SMARTY's merger update says that since August 2025 its customers have started to use Vodafone's network automatically too, at a growing number of shared sites.

SMARTY isn't a standard MVNO wholesale arrangement. The footer on SMARTY's about page names it as a trading name of Hutchison 3G UK Limited, the company behind Three, so there's no third-party deal between the two brands. In practice, this gives SMARTY customers full exposure to Three's network investments, including the ongoing 5G rollout, without any wholesale intermediary.

Three's coverage page says its 4G network covers 99% of the UK population, measured outdoors. 5G comes at no extra cost on every SMARTY SIM; all you need is a 5G-enabled phone.

Ofcom's Connected Nations 2025 report finds that 4G from at least one network now reaches 96% of the UK landmass, but coverage still differs across England, Scotland, Wales and Northern Ireland. 5G varies even more: individual networks report outdoor 5G coverage at between 64% and 89% of UK premises. A national figure won't tell you how your own village or stretch of coastline fares.

SMARTY and EE compared: terms, roaming and coverage

SMARTY is the simpler deal on terms. Coverage is the part you have to check for yourself.

SMARTY's signal comes from Three's masts and, since August 2025, shared Vodafone sites. EE runs its own network. Put the postcodes where you live, work and holiday into Ofcom's Map Your Mobile checker, which shows which network performs best in each area, before you switch.

EE's price rise page gives its own example: a SIM only plan at £25 a month on a 24-month contract costs £27.50 from 31 March 2026 and £30 from 31 March 2027. After the minimum term, EE's SIM only prices rise again each 1 March, and EE runs a credit check when you join. SMARTY advertises none of that.

If you want a price that doesn't climb each spring and a plan you can drop at the end of any month, SMARTY is the easier pick. If the coverage map shows EE is the only strong signal where you spend your time, that matters more than price or terms.

SMARTY support is web chat first

You can reach a person by web chat. SMARTY doesn't run a general phone line, and its contact page lists web chat with the Customer Care team from 8am to 8pm, seven days a week, plus the SMARTY Bot 24/7. SMARTY's accessibility page gives the one phone number, 0333 338 1047 (9am to 5pm, Monday to Friday), for customers with additional needs or in a vulnerable situation, plus a textphone on 0800 033 8011.

That gap catches people off guard.

Most UK mobile customers expect a number to ring when something goes wrong. SMARTY works differently. Web chat is the route to a real person, from 8am to 8pm; outside those hours you have the bot, the help centre or the community forum.

No call centre, but £12 buys 100GB. That's the trade-off, stated plainly.

If you regularly need hands-on account help, a network with phone support may suit you better.

Routine tasks (changing your data plan or checking your remaining data) go through the app without needing to contact anyone. The friction surfaces in complex billing disputes or number porting problems, where some people would rather talk it through on the phone. Know this before you switch.