You want to change networks, but your new SIM card won't work in your phone. Baffled, you call your new carrier, only to learn that your smartphone is locked to the first network, and there's not much you can do about it.

Of course, this isn't strictly true. If you're using an Android device, there's always something you can do. Here's how to SIM unlock your Android phone or tablet.

Does Rooting a Phone Unlock the SIM? No

Before learning how to unlock your Android phone's SIM, let's look at what unlocking the network/SIM is, and is not.

Unlocking the SIM requires a generated code that is input into your phone via the keypad. It's done to break the link between your phone and the network that shipped it. This enables you to insert a compatible SIM card from a different network and connect to their service.

Can you unlock your Android SIM for free?

However---and this key---unlocking the SIM does not root your phone or mobile internet-equipped tablet.

Rooting your phone unlocks the bootloader, which is a different thing entirely. Rooting a phone will not carrier-unlock it, but it will let you customize the operating system or install a new one.

Both types of unlock are legal, although a SIM unlock often requires help from the network/carrier.

Is Your Phone SIM Locked?

Unlocking your tablet or phone to a new network often isn't that difficult. Not all phones are SIM or network locked, anyway.

Phones bought directly from a manufacturer or third-party retailer like Motorola, OnePlus, or Amazon for an unsubsidized price (usually $500-$700) are more likely to be unlocked than phones purchased from carriers like Verizon, T-Mobile, or AT&T for subsidized prices (usually free to $200).

But how can you tell if your SIM is locked?

  • Check the device's documentation: if "unlocked" appears on the invoice, you can be confident it isn't locked to a carrier.
  • Try a new SIM card: if you pop in a SIM from a different carrier and it doesn't work, you know the phone is locked.
  • Contact your carrier: ring them up and ask if the phone is locked.

But if you've discovered that your Android phone is locked to a particular carrier/network, how can you unlock it?

Ask Your Carrier to Unlock Your Phone or Tablet for Free

Amazingly, you can get in touch with your carrier about SIM unlocking your phone or tablet.

Since February 2015, US cell phone owners have been able to request networks unlock their devices to switch carriers. A similar system is in place for phone owners in the European Union, and the United Kingdom.

Further, carriers must inform customers on their monthly bill whether the device is eligible for unlocking.

Begin by calling your carrier and asking if the phone is eligible. There is a clause on smartphones bought on contract, so if the initial two-year deal isn't yet up, you'll have to pay a fee. This will cancel the contract and give you the unlock code.

This leaves you free to use another SIM in your phone.

If you bought your phone outright from a network, it will typically be locked for 12 months. After this time, if the account is up to date, the network should surrender the unlock code.

How to Unlock the SIM on Your Android Phone or Tablet

To end the network/SIM lock, your network will need the IMEI number. The International Mobile Equipment Identity is a unique code used to identify your phone or tablet on any network.

In Android, there are two ways to find the IMEI number:

  1. Open the Phone app.
  2. In the dialer, enter *#06#.
  3. Make a note of the IMEI information.

Alternatively:

  1. Open Settings > About phone (on older phones, go to Settings > About phone > Status).
  2. Scroll down to find the IMEI Information and make a note of it.

When you contact your network, either by phone or through the website, this 15-digit string is all they need. The network should then provide you with a code to enable your device to use the new network's SIM card.

(Note that the full process can differ across networks. Also, be aware that your new network may require you to input a specific code to work with that carrier.)

While American carriers are not permitted to charge for this service, in the UK and Europe your network may charge a small administrative fee for unlocking your phone.

Meanwhile, if you have trouble with the "SIM not provisioned MM 2" error, we've offered some tips to help.

Related: How to Fix the SIM Not Provisioned MM 2 Error

Find a Reputable Smartphone Unlock Service

If your network is not accommodating requests to unlock your phone, some specialized websites provide the service.

However, we would advise only using such a service if there is no way your network will unlock the device. As such sites are unregulated, they're not always reliable. You can gain some protection by paying for the service via PayPal.

Try these sites (provided at your own risk) to unlock your phone or tablet SIM:

Note that regardless of the service you choose, there is no guarantee that it will unlock your smartphone or tablet SIM.

Related: Free SIM Card Unlock Sites

Avoid Android SIM Unlock App Scams

As we've seen, unlocking your Android's SIM is relatively simple. So much so that you won't need any SIM unlock apps.

These apps are fake and represent a risk to the security of your device and the data stored on it. They're scams and as such should be avoided.

So, don't head to Google Play to look for a SIM unlock tool. Similarly, don't search for any "phone unlock tools" on download sites, Bittorrent, or Usenet. These are typically laced with Trojans and other malware.

Safe, legal means exist for unlocking your smartphone's SIM/network relationship.

But while you should be cautious of SIM unlock app scams, Google Play does have useful apps for SIM card management.

Did You Unlock Your Device?

SIM unlocking your smartphone or tablet isn't ideal for everyone. We would recommend that you spend a good deal of time weighing up the pros and cons of this process. It's useful for some, such as if you're travelling overseas and don't have a dual SIM device, for example.

And if you're switching mobile network providers, make sure you're getting the best available deal!