It's said that the social network has request several US banks to share its customers' financial data, including checking account balances and card transactions.
According to The Wall Street Journal, the company has been in conversation with Wells Fargo, Citigroup, Chase and US Bancorp over the past year to talk about the possibility of new features for facebook Messenger.
Hosted on the app, these would include showing account balances or fraud alerts - and it comes as the company looks to expand its e-commerce footprint.
It's reported that one large bank has pulled out of talks due to privacy concerns.
Still, Facebook launched peer-to-peer Messenger payments three years ago - and payment options have continued to be added, including PayPal integration.
Regarding the reports, Wells Fargo declined to comment - but other banks named by the Wall Street Journal have given statements.
JPMorgan Chase's spokeswomen told the publication that the company isn't "sharing our customers' off-platform transaction data with these platforms, and have had to say no to some things as a result".
US Bancorp's chief communications officer Dana Ripley said: "We haven't shared any customer information or data to Facebook or any other technology platform."
Meanwhile, a Citigroup spokeswoman added: "While we regularly have conversations about potential partnerships, safeguarding the security and privacy of our customers' data and providing customer choice are paramount in everything we do."
Facebook has addressed the reports in a statement of its own, and insisted the development would have a positive impact on users.
A spokesperson said: "Like many online companies with commerce businesses, we partner with banks and credit card companies to offer services like customer chat or account management.
"Account linking enables people to receive real-time updates in Facebook Messenger where people can keep track of their transaction data like account balances, receipts, and shipping updates."