“buy now pay later” companies promised a credit revolution that would change the way people pay for things rising delinquencies and a slowing economy are clouding that outlook payment plans that allow shoppers to split up the cost of things such as clothing makeup and home appliances were all the rage last year the companies behind the plans saw their valuations surge scores of retailers rushed to add them at checkout block inc  formerly square inc in august announced a roughly 29 billion allstock deal for afterpay one of the biggest companies in the business