The Forum of Private Business named and shamed the brewer for the move, which Molson Coors confirmed had begun last month.
Suppliers were told invoices wouldn’t be processed for more than three months from receipt.
The Carling brewer’s finance director David Heede said: “There is a fundamental challenge for the beer industry – the total beer profit pool is down approximately 30% over the past five years.
“As part of a global initiative on working capital, we changed our supplier payment terms to be more consistent with industry standards and to be more competitive in the global beer market.
“Looking ahead is vital to the sustainability of the category and will ultimately benefit our consumers, customers and suppliers.”?An FPB spokesman said the move meant smaller businesses, which relied on Molson Coors for work, may end up waiting for more than a quarter before receiving any payment for their products and services.
The not-for-profit FPB said a “self-employed tradesman” highlighted the issue and said he could no longer afford to carry out contracts for Molson Coors as a result of the changes.
FPB chief executive Phil Orford has written to Molson Coors, urging the firm to reverse its decision and sign up to its Prompt Payment Code.