Atradius's global barometer of payment practices tracked 204 British businesses this summer, spanning a range of sectors including grocery.
Forty-one per cent of invoices had been paid late in the past six months, 59% of respondents had been asked by customers for extended terms, 57% had experienced unarranged payment delays and 46% had been asked for a credit rise.
"Payment behaviours are shifting," said Atradius UK and Ireland head of risk Marc Henstridge. "On average, in around half of all transactions, businesses are experiencing credit issues of one kind or another. This is particularly hard on smaller businesses supplying to fewer customers."
Some businesses were supporting one another in the face of straitened credit supply, but others had experienced tougher payment practices, he added.
Molson Coors, the brewer behind brands such as Carling, Grolsch and Cobra, was exposed by the Forum of Private Business this week for extending its supplier payment terms to more than three months.
The company informed suppliers invoices would not be processed for more than 90 days to keep terms "more consistent with the industry standard".
Experts said food and drink suppliers, particularly smaller, own-label manufacturers, had always been vulnerable to late payments and extensions to terms. While the grocery sector could, in some cases, see payment practices ease during peak trading periods as the balance of power shifted slightly to the supplier, terms did not always get better, they added.
"Although the multiples have improved their practices to an extent, the consensus is that the code of practice has had no real influence," said Baker TillyCorporate Finance manager, Angus Miller.