Fast Checkout: Apple Pay and PayPal Fast Checkout require you to apply any gift-card balance, StockX Credit, or discount code before selecting the wallet; they cannot be added afterward. Buy Now Pay Later: Affirm, Afterpay, Klarna, and PayPal Pay Later are available in the U.S., but eligibility depends on the order and payment provider. Payment Verification: StockX may place a temporary $1 or $15 authorization on a newly added payment method. It is normally released within 5 business days.