Credit ratings agency Moody's has downgraded the credit ratings of 15 worldwide banks and financial institutions.
In the UK, four major banks were affected by the move - and in a separate announcement, a fifth also had its credit rating lowered.
'Across the pond' in the US, financial institutions including Citigroup and Bank of America saw their credit ratings affected. According to Moody's global banking managing director Greg Bauer, the downgrade reflected the banks' risks, due to instability in the global financial markets.
Mr Bauer said that all of the banks that have had their credit ratings marked down had "significant exposure to the volatility and risk of outsized losses".
But how exactly could the downgrades affect banking customers? Robert Peston, BBC business editor, said that banks were worried that the credit downgrades may make it more difficult to borrow money. That could affect the cost of borrowing for customers.
A spokesperson for thinkbanking commented: "The credit rating downgrade for some major banks could signal bad news for many customers wishing to borrow money. If banks find it harder to borrow money themselves, this could push up the cost of credit for consumers and make it more difficult for them to get the financial products they want."