Leading US banks have warned that they could start charging companies and consumers for deposits if the US Federal Reserve cuts the interest it pays on bank reserves. Depositors already have to cope with near-zero interest rates, but paying just to leave money in the bank would be highly unusual and unwelcome for companies and households. The warning by bank executives highlights the dangers of one strategy the Fed could use to offset an eventual “tapering” of the $85bn a month in asset purchases that have fuelled global financial markets for the last year.