From My Learners, select Add payment method next to a child's name to securely save a card for future payments, via your institute's connected payment provider (Stripe, in most cases). This opens a standard card-entry form: card number, expiry, CVC, cardholder name, and billing address, handled entirely by the payment provider itself, not by Wise directly. Saving a card here means your institute can charge it for future invoices under that payment provider's terms, which are shown to you before you save.