They may be referring to the earned income tax credit or the child tax credit. Both are dependent on how much money you made last year.
The Earned Income Credit (EIC) is looking at the earned income on the return and the adjusted gross income to determine the amount of the credit. Earned income is money earned from any source where a service is performed either as an employee or a self employed individual.
The purpose of this credit is to help those people who are trying to make ends meet and working hard to accomplish that goal while working their way out of poverty. First the tax return looks at the earned income, then the adjusted gross income.
Beginning from $1 - $53,505 (2017 Table amounts) depending on filing status and the number of children it's likely you'll have EIC. The closer you get to the mid range the higher the credit and as your income increases the need is not as great and the credit is slowly reduced until out of range. For these reasons the credit can change dramatically from year to year. Click this link for more information.
EIC Charts and Qualifications
The second credit that might be considered is the following: Additional Child Tax Credit (ACTC) rule (This is a refundable credit.:( The Additional Child Tax Credit is a refundable credit that you may receive if your Child Tax Credit is greater than the total amount of income tax liability, as long as you had an earned income of at least $3,000. In other words the Child Tax Credit reduces your tax to zero before you are eligible for the refundable ACTC. The earned income rule continues to apply.
