The iPhone is arguably the most attractive thing among all the phone brands. It is also common these days to unlock the iPhone. Before unlocking any device, there are certain steps you need to take to make sure you don't run into any problems.
Whenever someone purchases a device from a contracted wireless service provider, the device may be considered network-locked and thus unable to be used with other service providers. Such a state is known as iPhone locked. You need to get the mobile phone unlock to get it working properly.
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Unlocking services are always carrier and country-specific, so you need to know the carrier and country you're locked in. Will perform IMEI verification services from authorized providers. Once you know the country and carrier, you will need to order a special service to unlock the advertised price.
Not all services support all iPhone models. So before you place an order, you need to make sure that you place the correct order with the correct model and IMEI.
Install the latest version of iTunes on your computer and make sure you have an internet connection. If you want to avoid data loss, backup is highly recommended.
Once you've updated your device to the latest iOS version, just insert the respective carrier's non-genuine SIM card. And follow the steps.
If the steps above don't work, or if you have an older version of iOS, you'll need to update to the latest version first.