How to unlock sim carrier

Apple does not lock/unlock iPhones. The carrier does that. Your iPhone will have to be unlocked by the carrier that it is locked to. Contact that carrier and ask about their requirements to get your iPhone unlocked for use with a different carrier.

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how to contact carrier that locked my iphone

It would be the carrier that was used when the device worked. You can contact 👉 Apple Support and see whether they can help identify the carrier that your iPhone is locked to.

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