Is there a way to tell a fake iPhone?

yonimar wrote:

Hi is there a way to tell a fake iphone ?

No.

There is no reliable means to remotely identify counterfeit.

Serial numbers can be copied, etc.

Not until after you open the box and try to) use it.

And too often, a legitimate device is Activation Locked and useless.

The All Too Common SAD Reality of Buying a used iPad/iPhone - Apple Community

Check here.

Check Your Service and Support Coverage - Apple Support