Iphone says iphone unavailable what should I do?

There is an Apple article that explains what to do if you have forgotten an iPhone or iPad passcode. Click on the following link: If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

If that option is not available, you will need to use a computer. See: If you forgot your iPhone passcode - Apple Support

If you were given the phone by someone else, there is a very important procedure that must be followed by the person who is giving the phone away.

What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

The folks at the Apple Store cannot do this. The person who was using the phone must do this.

If it's just unavailable, it can be restored without needing any information.

If it has an activation lock, tell its original owner to click here and submit an unlock request.

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See above. Neither of the two cases above require them to know the Apple ID, but if there's an activation lock, they will need the original purchase receipt.

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