Millions of terminals are shipped every year, and most of them share all the same basic features and functions. There are several basic types of credit card terminal: traditional terminals (with or without printers), wireless terminals, and virtual or software-based terminals.

Traditional terminal
Basic terminals include a magnetic stripe reader, a keypad to enter prices and other information, and a small display. The required printer can be built-in or a separate unit. When choosing between a built-in printer or separate units, remember that while it may be slightly easier to deal with one piece of equipment than two, the impact on your business either way will be minimal.

(Read more about different types of printers in the next section.)

Terminals have different types of displays: obviously, larger displays let you see more information at once. Displays are usually measured line lines and columns: an 8 x 20 display has 8 lines of text, 20 columns wide. Getting a backlit display lets you use the terminal even in low light conditions and is probably a good idea - backlights are standard on most new terminals in any case.

Keypads vary in size and number of keys. More keys typically give you the option to assign commonly-used functions to their own key; larger keypads can improve ease of use.

Wireless credit card terminal
Wireless credit card terminals provide a significant advantage for some businesses. For example, taxi drivers, seasonal businesses with temporary locations, and large lot businesses can all greatly increase efficiency by accepting credit cards wirelessly. However for most businesses, wireless credit card terminals are a needless expense: if it is never going to leave the counter, the wires pose no problem.

Wireless credit card terminals by necessity have printers built-in - your employees will not want to carry around two separate pieces of equipment. Important factors to consider when evaluating wireless terminals include battery life, range, weight, and shock-resistance - any terminal that gets carried around is going to be dropped occasionally.

Virtual terminal
If you do business exclusively over the phone or the Internet, you may not need a physical terminal at all. Your merchant account provider should be able to provide software that handles the transaction: you simply type in the credit card number and the software handles the authorization.

Other features
In addition to major credit cards, you will probably want a credit card terminal that accepts debit cards. Most do, but to complete a debit transaction, you also need a way for customers to enter their personal identification number (PIN). This can be done directly on the terminal or through a separate PIN pad. Separate PIN pads let you keep the terminal safely behind the counter and give customers convenient access to type in their code.

Issuing and accepting gift cards is another popular option, but not available on all terminals - so decide in advance if this is a feature you require. Many terminals also support additional forms of payment, such as phone cards and electronic bank transfers (EBT). The volume you see in these alternative payment methods should dictate whether you look for a terminal that supports them.

The address verification system (AVS) provides additional security for your transactions. By comparing the address on a customer's ID with the billing address of the credit card, AVS greatly cuts down on fraud. AVS is a standard feature on most terminals - do not buy a terminal without it.

Despite what some merchant account providers may imply, any credit card terminal can be used with any merchant account - the terminal just has to be programmed to connect to the right provider. If you do not like the terminals your merchant account provider has to offer, purchase yours elsewhere. Or, instantly compare multiple credit card terminal providers to find one to suit your needs.

Reliability
Overall reliability of credit card terminals is very good. Reliability is measured in mean time between failures (MTBF) or mean cycles between failures (MCBF), and is commonly in the 2-to-4 million transaction range. Because of this, you are not likely to need the 1 year warranty most terminals come with - but do accept it. As with any electronics, there is a small chance that you wind up with a faulty unit.