In this guide
- How we reviewed Smarty
- What is Smarty?
- Smarty vs iD Mobile
- Network
- Price and contracts
- Credit check
- Unused data
- Roaming
- Customer service
- Verdict
- Smarty vs Giffgaff
- Network
- Price
- Roaming
- Flexibility
- Verdict
- Smarty vs Spusu
- Price
- Price stability
- Roaming
- Customer service
- Verdict
- Smarty pros and cons
- How to get a Smarty SIM only deal
- Is Smarty worth it?
- Editorial policy
Smarty is a budget MVNO owned by Three, selling 30 day rolling plans with no credit check and a money-back scheme for unused data. This review looks at whether that combination holds up against the networks you would realistically consider instead, comparing Smarty with iD Mobile, Giffgaff, and Spusu.
Compare current Smarty SIM only deals
Reviewed by: Phil Brown, founder of SIM Only Finder. Phil previously worked in UK mobile retail at Three UK, advising customers on SIM plans, contracts, and network choices. He has spent over a decade running consumer comparison platforms and reviews networks and SIM-only deals based on that hands-on industry background. About the author
Last reviewed: July 2026. Updated regularly to reflect current plan pricing, network changes, and roaming policies.
How we reviewed Smarty
To put this guide together, we reviewed Smarty's current plans, roaming terms, credit check policy, and support channels in July 2026, checking prices against the live deals in our comparison engine and terms directly against each network's published information. The same checks were applied to every comparator figure in this guide. Where relevant, we have drawn on our own experience of advising customers on SIM plans and network choices.
What is Smarty?
Smarty is a mobile virtual network operator (MVNO) launched by Hutchison 3G UK, the company behind Three, and it runs on Three's network. Every plan is a 30 day rolling contract with unlimited UK calls and texts, 5G at no extra cost, EU roaming up to a 12GB monthly fair use limit, and no credit check. Its two distinctive features are the data discount, which credits you back for unused data on eligible plans, and Group Plans, which give 10% off every SIM for up to eight people on one account.
Smarty vs iD Mobile
iD Mobile is Smarty's closest structural rival: both are budget MVNOs running on Three, so the choice comes down to plan mechanics rather than signal.
Network
Both networks run on Three, so coverage, speeds, and 5G availability are the same wherever you are. Neither has an advantage here.
Edge: Draw.
Price and contracts
iD Mobile plans start from £6 per month, and its keenest prices come on 12 and 24 month contracts, such as 20GB for £6 per month over 24 months. Smarty's cheapest voice plan is £7 per month, but it buys 35GB on a contract you can leave next month. If you are willing to commit for two years, iD Mobile usually wins on price; if you are comparing rolling plans, Smarty gives you more data per pound.
Edge: Smarty.
Credit check
iD Mobile runs a credit check on all of its SIM only deals. Smarty runs none, on any plan. If your credit history is a concern, this decides it on its own, and our no credit check SIM only deals page covers the wider options.
Edge: Smarty.
Unused data
The two networks take opposite approaches. iD Mobile rolls unused data over into the following month, so a quiet month gives you a bigger allowance next month. Smarty's data discount instead credits money back on eligible plans, so a quiet month gives you a smaller bill. Rollover suits people whose usage swings around; money back suits people who would rather pay less.
Edge: Draw.
Roaming
Both include EU roaming, but the caps differ meaningfully. iD Mobile lets you use up to 30GB of your allowance in its included destinations, then charges a surcharge per GB. Smarty caps roaming at 12GB per month, then requires a data add-on or an EU Roaming Pass. For heavy data use abroad, iD Mobile's higher cap wins. Our SMARTY roaming guide covers the add-on routes in detail.
Edge: iD Mobile.
Customer service
Neither network offers phone support. Both handle support through live chat and their apps, and both keep costs down that way. There is nothing to separate them.
Edge: Draw.
Verdict
Smarty wins for flexibility: more data per pound on rolling terms, and no credit check anywhere. iD Mobile wins if you will commit to a long contract for a lower price, or if you want rollover and a bigger roaming cap. For most people comparing month to month, Smarty is the stronger pick.
Smarty vs Giffgaff
Giffgaff is the best known flexible budget network, running on O2 rather than Three, which makes this the comparison to read if coverage in your area differs between the two.
Network
Smarty runs on Three; Giffgaff runs on O2. Which is better depends on where you live and work, so check both coverage checkers at your postcode before deciding. Neither wins outright.
Edge: Draw.
Price
At the unlimited data tier, Giffgaff is currently cheaper at £14 per month against Smarty's £17. In the middle of the range, Smarty's allowances are aggressive, with 35GB at £7 and 95GB at £9 per month. Giffgaff takes the headline at the top end; Smarty is stronger per gigabyte in the mid tiers.
Edge: Draw.
Roaming
This is the clearest gap between the two. Smarty includes 12GB of EU roaming every month. Giffgaff caps EU roaming at 5GB per goodybag, and that cap is per plan rather than per month, which catches people out on longer trips. For anyone who travels in Europe regularly, Smarty is comfortably ahead.
Edge: Smarty.
Flexibility
Both are rolling, both skip the credit check, and both let you change plan month to month. Smarty adds Group Plans with 10% off each SIM for up to eight people, which Giffgaff has no equivalent for.
Edge: Smarty.
Verdict
Choose Giffgaff if you want the cheaper unlimited plan or O2 signal is better where you are. For everyone else, Smarty's bigger roaming allowance, mid-range value, and group discount make it the more complete package.
Smarty vs Spusu
Spusu is the budget benchmark on EE, and the network we rated highly in our Spusu review. This comparison is about the very cheapest end of the market.
Price
Spusu starts lower: £2.90 per month for 1GB, or £3.90 for 3GB. Smarty's entry point is £5 for a 2GB data-only plan, and £7 for its cheapest voice plan. If your priority is the lowest possible bill and you use little data, Spusu wins. If you want a lot of data cheaply, Smarty's 35GB at £7 is the better buy.
Edge: Spusu.
Price stability
Spusu commits to no price rises at all, so the price you join at is the price you keep. Smarty applies no annual rises either, but because plans renew monthly, the renewal price can change, and your protection is the freedom to leave. Spusu's guarantee is the stronger promise. Our mid-contract price rises guide explains how this works across networks.
Edge: Spusu.
Roaming
Spusu's EU roaming allowance scales with your plan tier, from 3GB up to 20GB, plus 500 roaming minutes and texts. Smarty gives a flat 12GB on every plan. On a cheap plan, Smarty's 12GB beats Spusu's 3GB; on Spusu's top tiers, Spusu edges ahead. For budget travellers, Smarty's flat allowance is the more useful shape.
Edge: Smarty.
Customer service
Neither offers UK phone support as standard, and both rely on chat and app-based service. Smarty holds a Trustpilot score of 4.0 from over 46,000 reviews and ranked first of 16 networks in Which?'s January 2025 customer satisfaction survey with a score of 82%, which is unusual credibility for a network at this price.
Edge: Smarty.
Verdict
Spusu is the pick for the smallest possible bill and a locked price. Smarty is the pick for data-heavy use on a budget, family group savings, and a bigger roaming allowance at the cheap end. Different users, so this one is a genuine split decision.
Smarty pros and cons
Pros:
- No credit check on any plan
- Every plan is 30 day rolling, so you can leave or change plan monthly without penalty
- No annual price rises
- Data discount credits you back for unused data on eligible plans
- EU roaming included on every plan, up to 12GB per month
- 5G included at no extra cost with no speed caps
- Group Plans give 10% off every SIM for up to eight people
- eSIM available on all plans
Cons:
- No phone support; service is live chat and app only
- Renewal prices can change month to month, so there is no way to lock a price in
- Roaming is capped at 12GB per month, and nothing is included outside Europe
- No 12 or 24 month contract option for a lower committed price
- No loyalty perks, entertainment extras, or inclusive international minutes
How to get a Smarty SIM only deal
Compare the current plans on our Smarty SIM only deals page, pick an allowance, and order a free SIM or eSIM. To keep your number, text PAC to 65075 from your old SIM and enter the code during sign-up; our Smarty switching guide walks through it step by step. If you would rather skip the plastic, compare eSIM deals across networks first.
Is Smarty worth it?
Yes, for most budget-focused users. Smarty won or drew every comparison above except on committed-contract pricing and heavy roaming, and its core offer of large allowances, no credit check, and month-to-month freedom is one of the strongest in the UK market. It is best for people who want a lot of data at a low price without being tied in, and for households that can stack the Group Plan discount.
The honest caveat is that Smarty's flexibility cuts both ways: with no fixed term available, you cannot lock in a price, and if the renewal price rises your only remedy is to leave. Anyone who values a guaranteed price for a year or more should weigh Spusu or a fixed-term iD Mobile deal instead. Ready to compare? See today's Smarty SIM only deals.
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Editorial policy
This guide is produced by the SIM Only Finder editorial team to help SIM only customers decide whether Smarty is the right network for them. Network terms, pricing, and roaming availability are checked regularly and updated to reflect current offers. Always confirm current terms directly with the network before signing up.
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