Not only is the use of debit cards overtaking credit cards, but other forces are reshaping the U.S. payment landscape, David Stewart, senior expert at McKinsey & Co., told the Association for Financial Professionals' Retail Treasury Forum recently in New York City.

To cope with these converging trends, companies will need to anticipate and adapt to ongoing liquidity constraints, as well as to the impact on customers of reduced access to credit. Companies will need to seek efficiencies, streamline and integrate systems and renegotiate payment terms, he said.

The economic slowdown is, of course, the overarching factor, with GDP expected to contract 3.4% this year, inch up to 1.2% growth in 2010; rise to 4.3% in 2011; and creep to 5% in 2012, Stewart said. The accompanying retreat from risk means banks are tightening credit standards or getting out of lending altogether, decreasing the supply of credit or making it available at a premium, he said.