Final answer:
The tax credit a parent of three dependent children can use is primarily based on the Earned Income Tax Credit, which varies according to income and number of children. In 2013, for a family with two children, the phase-out of the credit began after $17,530 in income. However, for the current tax year, the exact tax credit amounts should be verified as tax laws and amounts change frequently.
Step-by-step explanation:
The amount of tax credits a parent of three dependent children can use depends on the tax year and the specifics of various tax credit programs such as the Earned Income Tax Credit (EITC). The EITC is designed to help low- to moderate-income workers and families get a tax break. If you qualify, you can use the credit to reduce the taxes you owe - and possibly increase your refund. The EITC amount depends on a family's income and number of children.
For a single parent with two children, the EITC provides a significant tax credit, which is subject to income limits and phase-outs. For example, in 2013, a single-parent family with two children could receive the earned income tax credit until their income reaches $46,227, with the credit not being reduced while earnings rise from $13,430 to $17,530 and then being reduced slowly for each dollar earned above $17,530.
However, since the information provided is for the year 2013, and tax laws change frequently, the parent should check the most current tax year's guidelines for the accurate credit amount for having three dependent children.