Citizens Bank started offering in-store and online point of sale financing options, including fixed monthly installments, to buyers of Apple iPhones in 2016. Within a year, the bank was building scale on the buy now, pay later (BNPL) platform it had built by adding partners in new merchant sectors, including Microsoft and Horizon Fitness. Over five million consumers have received $6.40 billion in BNPL loans from Citizens. Last month, the bank launched Citizens Pay, making it available to merchants as a consumer-facing brand. Unlike most fintechs that offer BNPL installment loans, Citizen...