IAGIM
(A Locum International non-profit research organisation)
Credit card (Visa, Amex & Master) companies routinely request the identification number on the back of the card. This is an added security procedure to protect the card owner. Always provide this ID number for your protection and remember the exact credit card billing address is very important to supply accurately to prevent long authorization delays.
 
Back of Card
Visa / Master Card - 3 numbers
Amex - 4 numbers