Everything extra you need to know about Smart SIM. From how it works to troubleshooting and usage tips.

How it works 🤔

What is Smart SIM?

Smart SIM is a data-only SIM that gives you access to 400+ essential apps both in the UK and abroad. It works alongside your main SIM to keep you connected when your primary SIM loses signal or you’re travelling.

Does Smart SIM replace my main SIM?

No. Smart SIM doesn’t replace your main SIM or number. It’s designed to work alongside your existing SIM to boost connectivity or help you roam affordably.

How does Smart SIM work in the UK?

Smart SIM keeps you connected to essential apps by using the UK’s major networks. It’s like a backup plan for when your main SIM loses signal.

How does Smart SIM work abroad?

Smart SIM gives you access to 400+ supported apps when travelling, without relying on expensive roaming or patchy hotel wifi. Just switch to your Smart SIM and stay connected on the go.

Coverage, usage, and limits 📶

Which apps work on Smart SIM?

Smart SIM only works with a list of approved apps, focused on travel, navigation, messaging, and essential services. You can see the full list here.

Why can’t I use social media or streaming apps?

To keep Smart SIM affordable for everyone, we only support apps that are essential for travel and communication. Apps like TikTok or YouTube would make it too expensive.

Can I use data for other apps?

No, Smart SIM will only work for the approved apps. If you need full data access, check out our Classic SIM plans instead.

Does Smart SIM come with a phone number?

Technically yes, but it’s inactive. You can’t make calls or send texts using the Smart SIM.

Can I use the Smart SIM to call 999?

No. Since Smart SIM is data-only, emergency calls like 999 won’t work. Use your primary SIM for emergency calls, they’re free anywhere in the world.

Billing and compatibility 💸

How much does Smart SIM cost internationally?

There’s no extra charge to use Smart SIM abroad. It’s covered by your monthly or yearly Smart SIM payment.

I already have 2 SIMs, can I still use Smart SIM?

Most phones only allow two active SIMs at once (one for calls/texts, one for data). Check your phone’s settings or model specs before adding a third SIM.

Setup and troubleshooting ⚙️

How do I check if my Smart SIM is working?

We've made a handy in app test, to find out more click here.

I can’t see the Telnyx or SIM Toolkit app on my Android

Delete and reinstall the Smart SIM (using the same QR code). This should make the SIM Toolkit app appear in your app drawer.

Why can’t I use a VPN with Smart SIM?

Smart SIM traffic is already encrypted. VPNs interfere with app access, so you’ll need to disable your VPN while using Smart SIM. On iPhone, you can set up a Shortcut to turn it back on automatically when you switch back to your main SIM.

Can Smart SIM connect to satellite networks on planes or boats?

No. Smart SIM doesn’t support Maritime or Aeroplane Satellite Networks. You can check the full list of supported countries

Switching between SIMs 🔄

Can I switch to Smart SIM temporarily?

Yes, you can manually switch to your Smart SIM any time, or set up automated switching when you lose signal.

Can I enable automatic switching between SIMs?

Yes. On most devices, you can enable Allow Mobile Data Switching in your settings. This lets your phone switch to Smart SIM when your main SIM has no signal.