Most buy now, pay later (BNPL) purchases initiated through fintechs are authorized outside of the global card networks yet the vast majority of those transactions are paid off using a global brand debit card. New Visa cards from two BNPL fintechs will initiate more transactions over the Visa network.

Klarna’s debit card will connect to Visa Flexible Credential (VFC) technology, which provides cardholders with multiple payment options from a single credential. The Zilch Visa product will function as a debit card when tap and pay is used in-store or as a credit card when a cardholde...