NEED HELP [ASAP]

This guy wants to trade my iPhone X (the one I refunded) and $600 for a good ass pc. But I’m afraid if he tries to activate the phone, it will come up as lost or stolen... A lot of people say It’ll be fine and it hasn’t for them, but has it really been fine?

Need to know ASAP, I’m meeting early with him tomorrow possibly.

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Update: I used checkmend and the report passed with flying colors. Nothing reported or anything sus. (And no it isn’t some fake ass site, a lot of extremely reputable sites vouch for it).

Reset the settings on the iPhone to default and clear all iCloud account remains. It will come up as lost only if YOU report it as missing on the findmyiphone website, it will not do it by itself automatically.

Removing the iCloud from the iPhone is crucial when selling it.