You file when you have income and don't file when you don't. You don't have to file an extra report saying you had no income when you don't.
Yes, you could file a return with all zeroes (if you had no income), or with your income showing that your income was less than $6000 or $10,000 or $12,000 (depending on the year and the situation) and calculating no tax owed, but there's really no point. It will cost about $80 per return to buy the software, and 2013 and 2014 may not even be available any longer. And returns with all zeroes may just get tossed in the trash instead of keyed into the computer system anyway.
