One way districts can enable funding portability is with the use of student-based allocation formulas that allocate funds to districts and schools based on enrollment of students and student types. The student-based allocation model enables "pocketbook power," creating incentives for schools to attract students, keep full enrollment, and demonstrate excellent student performance. Student-based allocation models (also known as "weighted student funding") have been around for two decades, but not always as a mechanism to enable choice and accountability. Some policymakers implemented these kinds of policies to create more financial equity across schools, or as a component of school-based decision-making. This brief explains the need for a student-based allocation system in the context of school choice, and provides an overview of the key features that enable student choice across schools within districts. Specifically, the brief covers: (1) How traditional staffing-based allocation schemes clash with choice policies; (2) How student-based allocation can enable more portable funding across schools; and (3) Whether it is feasible for schools to lose funds as students choose other schools. (Contains 6 figures and 9 footnotes.)