The ESA statute (A.R.S. §15-2402(B)(3)) requires that while a parent has a contract with the ESA program, at no time can a student receive both ESA and BCF/STO money. This means that if the parent applies for the ESA program during the academic year and signs an ESA contract, any and all BCF/STO tuition aid money paid to the private school for that academic year must be refunded to the BCF/STO regardless of when the ESA contract was signed during the academic year.
For example, a parent applies for and receives BCF/STO tuition aid in spring 2016 for the upcoming 2016/17 academic year and the BCF/STO sends the tuition aid money to the private school in the spring. In October of the school year the parent decides to apply for ESA funding and signs a contract with the ESA program. Even though the contract was signed in October it applies retroactively to the beginning of the academic year. Therefore the student is no longer eligible for any BCF/STO money for that academic year and the private school must refund the full BCF/STO tuition aid that was paid in the spring.