For questions regarding GSK CPSIA Certificates please contact GlaxoSmithKline Customer Response Center at 1-888-825-5249. GlaxoSmithKline's Customer Response Center's hours of operation are M-T, Th-F 8:30 am - 5:30 pm ET and W 8:30 am - 4:00 pm ET. The Customer Response Center is not operational on the weekends or during holidays. https://contactus.gsk.com/