Always ask for the CNIC (Natinal Identity Card)
As a person can use the CNIC of another person, just by showing the CNIC is not enough, do a video call on Whatsapp to check the face of the person matches with the sent CNIC.
Also check CNIC is not photoshopped.
Write the name of the person via Facebook Search Box, and check the rating of the person either he has scammed or not.
Always deal with a person who is professional and use professional words when he talks to you.
Don't deal with the person who is not at English, and he doesn't communicate professionally.
If he doesn't follow above rules, don't deal with him.
