The credits offered on property or income taxes would be up to $4,100 per year and apply to any family making less than $75,000 a year.
Sanford has mentioned the proposal in his executive budget and last month's State of the State Speech.
"By enacting a wide-scale, universal credit, we will provide more options for all students to receive an adequate education and will take a step toward advancing equity funding for education," Sanford wrote in his budget proposal.
He planned to discuss specifics of the "Put Parents in Charge Act" in a news conference Thursday. Home school families also planned to attend.
"This will empower parents of children attending school and give them choices as to where their child would go to school," said Rep. Doug Smith, R-Spartanburg.
"One of the good things this plan tries to do is dispel the argument that low-income parents are only interested in sending their children to public schools. They want options and this plan focuses on that issue as well as tax credits," Smith said.
Jan McCarthy, president of the South Carolina Education Association, said the proposal would not benefit working class families.
"Most working class families cannot afford private school," she said, noting that the tax credit would only partially cover tuition.
House Minority Leader James Smith, D-Columbia, said the plan is "a way to backdoor vouchers and take needed funds from public education."
But Sanford spokesman Will Folks said school choice will help reform an educational system that has consistently ranked near the bottom.
"The governor believes strongly that giving parents more choices in the education marketplace is central to real education reform in South Carolina," Folks said. "The governor is committed to providing options and incentives for parents to determine what's in the best interest of their children."