PermitHub is a comprehensive full-stack college permission automation platform that digitizes the entire student request lifecycle, including leave applications, on-duty (OD) approvals, and hostel outpass management. The system replaces all paper-based processes with a structured, hierarchical digital workflow that seamlessly connects every stakeholder in an academic institution — students, faculty (mentors, class advisors, event coordinators), heads of departments (HOD), wardens, administrative officers (AO), principals, security personnel, and parents. Built on a Spring Boot 3.1.5 backend with a React 18 frontend and communicating via RESTful APIs, the platform enforces role-based access control with strict departmental isolation, skip-duplicate approval logic, and real-time push notifications to minimize approval latency. A distinctive feature is the WhatsApp-integrated parental approval chain with time-limited tokens and encrypted QR code generation for gate-level security verification. Experimental evaluation across a pilot deployment demonstrates an approximately 78% reduction in average approval processing time, near complete elimination of physical paperwork, and measurable improvements in stakeholder satisfaction and institutional transparency.