The card reader (a.k.a card swipe or MSR) must be configured to send track 2 only with no carriage return between the tracks. Configuring a credit card reader usually involves installing and using the manufacturer-provided configuration software, or, in the case of a keyboard-wedge reader, typing a sequence of special keystrokes.
To configure your card reader, consult the manufacturer's documentation or contact them for support. Documentation can usually be found on their website.
If you have ordered the MagTek Mini USB card reader, you can view our configuration guide here.
For your convenience, here are links to the documentation pages for a some popular card reader brands:
To ensure your card reader is configured correctly, do a test swipe while your cursor is placed in a text editor (e.g. Notepad on Windows, TextEdit on Mac).
Here is an example of a swipe from a correctly configured card reader:
Here is an example of a swipe from an incorrectly configured card reader with a carriage return between tracks: