When a phone or tablet is locked, it'll only work with the network that it was bought from. In order to take advantage of the SMARTY plans, you may need to unlock your device.
Some mobile service providers run on the same network. For example, Giffgaff and Tesco mobile run on the O2 network. Therefore, if you have an O2 locked device and insert a Giffgaff SIM it will still work. However, if you insert a SMARTY SIM into that same device, it won't work as the device is locked to the O2 network and SMARTY SIMs run on the Three network. This will be the same for any other network SIM you try and use with a locked device.
How can I tell if a device is locked?
Just insert someone else’s SIM from another network (from your current provider) into your device and see if it works. If it does, your device is unlocked. If it doesn't, then your device needs unlocking.
You may also see a prompt asking you to enter SIM Network Unlock PIN.
How do I unlock my device?
You've got 2 options.
You could take your device to an independent phone shop on the high street and they'll charge about £15 to unlock it.
But we'd recommend calling your previous mobile provider and asking them to help. Every network has the ability to unlock a device, but some networks do charge a fee for this.
How long does it take to unlock a device?
The time needed to unlock a device depends on the network processing the change.
Some networks will unlock a device straight away, while others may take a bit longer. In some cases, the unlocking process could take up to 30 days.
Is it illegal to unlock a phone or tablet?
No, you're perfectly entitled to unlock your device. Just be aware that you do risk invalidating your warranty when you do so.