Shares in PayPal fell on Thursday after Amazon said it was removing Venmo as a payment option.
“Due to recent changes," Venmo will no longer be accepted on Amazon from 10 January, says Venmo on its site. However, Amazon will still accept Venmo debit and credit cards.
Amazon only added Venmo - which has around 90 million users - last October. At the time, the e-commerce giant said "our goal is to meet the needs and preferences of every Amazon customer".
Amazon has not provided an explanation for the reversal but a Venmo spokesperson told CNBC: "We have a strong relationship with Amazon and look forward to continuing to build on it."
Shares in Venmo parent PayPal slid more than two per cent in afternoon trading.