The very first thing that you require taking into account while selecting a credit card machine is whether you accept payments via credit card either by phone or by mail. In both these cases your primary concern should be the ease of use since you have to key in your payments manually using a key pad. 

Of course you may not have any compatibility problem since most of the terminals are designed to use key pads for manual entries. The only thing you require is a reliable terminal and a printer that would allow you to print out the transaction details for customer and your own records. 

Printers and machine can come as coupled or integrated devices. Programming with such machine is a simple task and they are easy to use. The next issue for consideration would be whether your customers are present while presenting their credit cards.

In the traditional stores they will be present with their credit cards. In these cases the integrated credit card terminal should be your choice for affecting the counter space economy. Integrated devices being all in one require much less electrical outlets for their operation. 

Besides the traditional credit card, customers are growingly using the debit cards where chances of fraud are fewer as the customer pays from the available funds in his account. In the process they do not pay any interest. The processing remains the same. It is conducted using the paid, free or wireless credit card machine.