Correct email address and correct phone number must be mandatory for any order where payment is received through credit card.
You must ask for complete customer information and make it mandatory for him to provide you contact and tracebility information i.e. photo id or address proof.
Never process the credit card from your terminal on behalf of the customer without his written consent. If card holder disputes anytime and your IP address is found to be used for the transaction without written permission proof, it may create legal problems for you.
You must ask the customer for his/her identification proof ie. Driving License, Passport copy, any other document where his address, photo, signature etc can be verified.
You may also ask for the used credit card front and back photocopies or his credit card bank statement.
In case of product delivery, additionally, you must keep the proof of delivery or AWB no of courier company for all the orders up to one year after the date of order.