an iPhone credit card application enables an iPhone user to accept credit cards. Many applications already exist and more are added on a daily basis.
Some iPhone credit card apps turn an iPhone into a virtual terminal. Others can trun your cell phone into a full credit card wireless device.
You need to decide if you wish to add hardware (a card swiper) and turn your iPhone into a swipe machine, or stick to the software world and key in transaction.
One way or another you'll need to open a merchant account and connect your iPhone to a payment gateway. Some providers have it all and others supply the software only, leave it to you to connect to a payment gateway and a merchant account.
Get ready to fill in some personal and business details when applying for a merchant account. Your acquirer must understand who he's dealing with to have you approved.