The earned income tax credit and additional child tax credit are "refundable," meaning filers can claim a refund without tax liability. Here's who qualifies.

The federal Earned Income Tax Credit is designed for low to moderate-income wage earners and is fully refundable, meaning even those who do not earn enough money to have taxes withheld are eligible. The Internal Revenue Service is reminding tax filers about a key credit worth up to $7,830.

About one in five eligible filers overlook this credit, the IRS said. Certain filers can receive up to $7,830 more back in their refunds when claiming the credit.