Typically, one of our mini-kegs can be stored for several months, provided that you store it in a cool place. Refrigeration is preferable, but not completely necessary.
We encourage retailers to keep them cold so that the shelf life with you, the consumer, is maximized. Once you get it home, storage in a cooler would be ideal, but cool spaces such as closets or basements will work!
You can probably store it longer, especially if refrigerated with the top vent closed between pours, but our concern is that the carbonation will start to suffer.