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In order to use the iPad with another carrier, you would first need to unlock the phone from the original carrier.
Take a look at this article for help with getting this accomplished:
iPhone: About unlocking
Follow these instructions to initiate the unlocking process for your iPhone:
- Check if your carrier offers unlocking. Only your carrier can unlock your iPhone.
- Contact your carrier and request an unlock.
- You may need to meet certain requirements to qualify for unlocking. After your carrier submits the unlocking request, it may take up to seven days.
- Once you receive confirmation from your carrier that your iPhone unlock has been processed, proceed to the next section.
If you have a SIM card from a carrier that is different from your current carrier, and you've received confirmation from your current carrier that your iPhone is unlocked, follow these steps:
- Eject your SIM card and insert the new SIM card.
- Complete the setup process.
If you do not currently have another SIM card you can use, follow these steps to complete the process:
If you experience issues or receive the following error message displayed in iTunes or on your device, follow the steps below:"The SIM card inserted in this iPhone does not appear to be supported. Only compatible SIM cards from a supported carrier may be used to activate iPhone. Please insert the SIM card that came with your iPhone or visit a supported carrier store."
All the very best,