It is very important for financial institutions to have a quick method of verifying the validity of credit card numbers obtained from various customers or associates. While these checks can be performed online, the lack of an Internet connection can prove to be problematic.

CC Check is a very simple and lightweight OS X app that provides this functionality, without requiring an active Internet connection. It adds an unobtrusive icon to your Mac's menu bar that can be accessed to quickly assess the validity of credit card numbers.

It is important to note, however, that this app uses the Luhn Algorithm to determine whether or not a credit card number is valid, but cannot verify if it is currently active.

In essence, there is little to say regarding CC Check's intended function, as it is relatively self-explanatory. It can verify numerous credit card companies, including Visa, MasterCard, American Express and Maestro. Also, it automatically detects the issuer based on the inserted card number.

CC Check features a rather puzzling menu design that makes the application more difficult to use that it should be. When you click on its menu bar icon, a drop down menu is displayed, containing a few simple instructions, along with the Open and Quit functions.

It is hard to understand why the credit card checking feature cannot be brought up with a single mouse click, as it would greatly speed up the process. Optionally, the drop-down menu could still be accessed by right-clicking the icon, in case first-time users need to view the provided instructions.

While the Open function can be triggered with a keyboard shortcut, this is only possible once the application's menu has been brought up, making the shortcut redundant. It would help if you could set up a custom, system-wide combination, to access the app more easily.

CC Check is a simple tool with a specific target audience, and it performs its intended function adequately. Sadly, however, given that users who are interested in such an application are most likely looking to save time, the fact that it does not support one-click operation reduces its usefulness.