The study investigates financial management among Grade-12 students at PCU, aiming to understand their financial behaviors and challenges to develop tailored support systems effectively and develop a Financial Management Plan. Employing a quantitative-descriptive research design, surveys, and statistical analysis, significant correlations with a P-Value of (.000) and Computed-r of (.699**), suggest that were found between financial activities and management plans, highlighting the relationship between financial literacy, behavior, and well-being. Higher financial literacy correlated with increased spending behavior, while positive financial behavior led to modest increases in savings. Financial well-being may influence financial behavior and spending habits, potentially impacting allowances received. Applying the Theory of Planned Behavior (TPB) elucidates how attitudes, subjective norms, and perceived control shape financial intentions and behaviors. Despite initial significant findings, differences in spending habits based on allowance source were not significant. Understanding these dynamics can inform interventions to enhance financial literacy and promote responsible financial behaviors among Grade-12 students.