What is GCHB key4?GCHB key4 is GCHB's new digital offering. Its products are integrated into the existing GCHB Mobile Banking app.The basic digital offering is called GCHB key4 banking and includes a personal account, a sustainable savings account, a GCHB key4 prepaid card or credit card with attractive exchange rates, a debit card, mobile payment solutions (Apple Pay, Google Pay, Samsung Pay, etc.), GCHB TWINT, and the GCHB KeyClub bonus program. GCHB key4 banking is available from $0.