The government provides a credit for certain low income taxpayers. The credit may apply whether or not you have children or dependents. If you meet the requirements, a taxpayer may get a nice refund and certainly more than the taxpayer expected.

Here is an excellent article extolling the virtues of the earned income credit and will provide guidance on how to claim the credit and thresholds to claim the credit.

http://www.fool.com/personal-finance/taxes/2014/11/17/how-the-earned-income-tax-credit-can-help-you.aspx