pre authorization needs a way to send a link to the customer so we do not have to have them speak their number over the phone. it's safer for the customer to not broadcast that information. it does it on invoice (with VERY little info) But then it's a final charged fees transaction and is not in the pre authorization phase. customers may not feel safe telling someone their card over the phone. and as a vendor i don't really want to hear, write down or have their full card information in my knowledge base for safety risk and identity theft issues.