Single filers under the age of 65 with gross incomes less than $10,150 for the 2014 calendar year are not required to file a tax return. Individuals 65 years of age or older that earned less than $11,700 need not file a return, according to about.com tax experts.
Married couples filing jointly are not required to file returns when combined earnings were less than $20,500 -or $22,700 if both spouses are 65 or older. Married persons filing separately must file a return if earnings exceeded $3,950.
Single dependents under 65 must file a 2014 return if either unearned or earned income was more than $2,550 or $7,750, respectively. Married dependents must file a return if either unearned or earned income exceeded $1,000 or $6,200, respectively.