Okay, you accept an order from online or over the phone, and the person reads to you their credit card details. The payment goes through, and all looks good. This is all very easy to setup and do in our point of sale software.
The problem today was that a cardholder queried one such payment. Although the credit card was valid and the customer was known to the retailer it was impossible for one of our clients to prove the cardholder approved the transaction. He said he did not know about it, the person who processed the payment was not sure if it was him and as such the credit card transaction was cancelled.
It is a risk. You need to be aware of if you plan to accept such payments.