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Honest Mobile Smart SIM: Multi-network SIM with free roaming

17th March 2025

Honest Mobile Smart SIM

Honest Mobile is a name you might not have come across before, and if you have, you likely know it as an MVNO (mobile virtual network operator) providing access to Three’s mobile network.

That’s what it started as, and this service is still offered through Honest Mobile’s ‘Classic SIM’, but the company now also sells what it calls a ‘Smart SIM’, and this is very different to anything we’ve seen from other UK networks.

Because rather than just limiting you to Three’s connectivity, this Smart SIM can also connect to EE’s and O2’s networks, meaning that if you’re ever in an area with no signal on one of the three, it can connect to another.

It’s a powerful tool then, but it’s not without limitations. Below, you’ll find everything you need to know about Honest Mobile’s Smart SIM.

What is the Honest Mobile Smart SIM?

Honest Mobile’s Smart SIM is a single eSIM that can connect to three UK networks, namely EE, Three, and O2. Those three along with Vodafone are the only UK networks that actually have their own spectrum, so with the Honest Mobile eSIM you have access to three of the four proper mobile networks in the UK.

However, this isn’t designed to be your main SIM card – it’s a data-only SIM, so you’ll still need another SIM for calls and texts (though you can use the likes of WhatsApp for voice calls and messaging), and there are also restrictions on what you can do with that data, which we’ll cover in more detail below.

So the Honest Mobile Smart SIM is essentially designed as a backup SIM that will kick in when you lose signal on your main one, but it also comes with free roaming in over 180 countries. As such, it might make sense to have Vodafone (or a Vodafone MVNO) as your main network provider, so that between the two you have all four main networks covered.

How much does it cost and how do you get it?

The Honest Mobile Smart SIM costs just £10 per month, or you can get a massive discount if you commit to a 12-month plan, with this coming out at just £3.75 per month at the time of writing.

It’s available to order from Honest Mobile, and since this is a secondary SIM card you don’t need to cancel your current mobile plan to get it (and indeed you shouldn’t), but as it’s eSIM-only you will need a phone with eSIM capabilities.

Order Smart SIM

What does and doesn’t the Smart SIM work with?

Honest Mobile’s Smart SIM works with over 200 apps currently, and it’s likely that number will increase, as Honest Mobile has so far been rapidly expanding what it supports.

These apps include the likes of WhatsApp, Google Maps, Uber, Monzo, Citymapper, PayPal, Wise, Google Translate, Uber, and many others. You can see the full list here, but the selection mostly includes messaging, navigation, finance, travel, and search apps.

While that’s a large number of apps, that also means there’s a vast number of apps that you can’t currently use the Honest Mobile Smart SIM with, and it won’t work with all features of some apps either – you should stick with your main SIM for social media, streaming, web browsing, video calls, and email.

The Smart SIM then is more intended for what Honest Mobile describes as “essential” apps, and while the number of supported apps will likely grow, we wouldn’t expect that focus to change.

Can you roam with the Honest Mobile Smart SIM?

Yes, in fact roaming is one of the Honest Mobile Smart SIM’s main selling points. You can roam in over 180 countries, including the likes of the US, Canada, France, Germany, Spain, Italy, China, Japan, Argentina, Brazil, Australia, New Zealand, Egypt, and more. You can find the full list of destinations here.

Roaming comes at no extra cost, and you’ll be connected to local networks in these countries, much like you would when roaming with other UK networks.

But that’s a better selection of roaming destinations than you’ll get as standard with most UK networks – though the same restrictions on which apps and functions you can use apply when roaming.

Is this a replacement for your main SIM card?

No, with Honest Mobile’s Smart SIM you won’t have a phone number, and you will only be able to use select apps and functions, so you’ll still need a standard SIM too. Think of the Smart SIM as a backup or companion to your main SIM, designed to boost your signal and unlock affordable roaming.

Are there any data limits or fair usage restrictions?

The Honest Mobile Smart SIM comes with unlimited data and free roaming, with no hidden charges or fair usage restrictions.

That said, it is inherently limited for the reasons detailed above – namely that it only works with select apps, and can’t be used to stream, web browse, make video calls, or do certain other data-hungry activities.

Can you get the Smart SIM as a physical SIM card?

Currently Honest Mobile’s Smart SIM is only available as an eSIM, but the network has stated that if enough people want a physical SIM version, then one might be offered in future.

Of course, whether eSIM or physical SIM, it will still only work in dual-SIM phones, as you need a ‘main’ SIM card running alongside it.

Editorial Manager

James has been writing for us for over 10 years. Currently, he is Editorial Manager for our group of companies ( 3G.co.uk, 4G.co.uk and 5G.co.uk) and sub-editor at TechRadar. He specialises in smartphones, mobile networks/ technology, tablets, and wearables.

In the past, James has also written for T3, Digital Camera World, Clarity Media, Smart TV Radar, and others, with work on the web, in print and on TV. He has a film studies degree from the University of Kent, Canterbury, and has over a decade’s worth of professional writing experience.

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