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Smarty mobile deals

Smarty is a no-frills network offering some of the cheapest unlimited data plans in the UK.

Prices correct as of August 2026. We may earn commission when you click through — this never affects our rankings.

Smarty review 2026

Smarty is a SIM only network that runs on Three's infrastructure. It launched in 2017 and has built a reputation as one of the more transparent and affordable options in the UK. Unlike most networks, Smarty credits you back for any data you don't use at the end of each month. Plans are available on a 30-day rolling basis and on 1-month, 3-month and 12-month terms. Smarty's pricing tends to be consistently among the lowest available, particularly for unlimited data. It's aimed at people who want a no-frills deal with honest pricing rather than complex bundle features.

Coverage

Smarty uses Three's network for coverage. Three has strong 4G and 5G presence in cities and large towns, including good indoor coverage in urban areas. However, Three's rural coverage is weaker than EE or O2 — there are meaningful gaps in remote areas of the UK. If you live or regularly travel in rural Scotland, Wales or parts of northern England, it's worth checking Three's coverage map for your specific area before signing up.

Pricing

Smarty is consistently one of the most competitively priced networks in the UK, particularly at the unlimited end. Its pricing is straightforward — there are no bundles, rewards programmes or add-ons to navigate. For unlimited data plans, Smarty regularly undercuts both major networks and many other MVNOs. The data refund feature adds further effective value: if you don't use your full allowance, you get money back automatically at the end of the month. There are no setup fees and no credit checks required.

Roaming

EU roaming is included on most Smarty plans at no extra cost, covering calls, texts and data in EU member states. Smarty uses Three's international roaming agreements for this. Outside the EU, separate charges apply — check Smarty's website for rates before travelling further afield.

Key features

Unused data refunded
If you don't use your full data allowance, Smarty automatically credits you back for what's left at the end of the month. This is one of the more unusual and customer-friendly features in the UK mobile market.
Consistently low prices
Smarty regularly offers some of the cheapest unlimited data plans available, often significantly cheaper than the same allowance from major networks.
No annual price rises
Smarty does not apply mid-contract price increases. The price you sign up for is what you'll pay.
EU roaming included
Roaming in EU countries is included on most Smarty plans at no extra charge, using Three's international roaming agreements.

Customer service

Smarty is an online-only service with no physical stores. Support is available through the Smarty website via live chat and a help centre — there is no traditional phone helpline. For a budget-focused MVNO, the support offering is functional but minimal. It's well-suited to people who are comfortable managing things online and rarely need to contact their network, but it's not the right choice if you value being able to call someone when something goes wrong.

Who should choose Smarty?

Smarty is the right choice if your priority is paying as little as possible for a large or unlimited data allowance, and you're based in or near a city or town with strong Three coverage. The data refund feature makes it particularly good value for people whose usage varies month to month.

Worth knowing

Smarty is not a good fit if you spend significant time in rural areas where Three's coverage is thin. It's also a very bare-bones service — there are no rewards programmes, extras or in-store support.

Verdict

Smarty is the clearest choice in the UK for anyone whose priority is getting the most data for the least money. The combination of low prices, the data refund feature and no annual price rises makes it hard to beat on pure value — particularly for unlimited data. The trade-offs are limited rural coverage on Three's network and a minimal support model. If you live or work in a city and are comfortable managing everything online, Smarty is one of the strongest-value SIM only options available in 2026.

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Frequently asked questions

Is Smarty any good in 2026?
Yes, particularly for value. Smarty is one of the cheapest unlimited data networks in the UK and runs on Three's infrastructure, which has strong urban coverage. Its data refund feature — where unused data is credited back to you — is genuinely unusual in the market. The main limitations are Three's rural coverage gaps and minimal customer support.
What network does Smarty use?
Smarty runs on Three's UK network infrastructure. You get Three's 4G and 5G coverage — strong in cities and towns, patchier in rural areas.
Does Smarty refund unused data?
Yes. If you don't use all of your monthly data allowance, Smarty automatically calculates the unused portion and credits you back for it at the end of the billing cycle. This happens without you needing to do anything — it's applied automatically to your next bill.
Does Smarty include EU roaming?
Yes. Most Smarty plans include EU roaming at no extra cost, covering calls, texts and data across EU member states. Outside the EU, standard roaming charges apply.