According to the Bristol-based business, the haul takes its total for the year so far up to £4.03m.
However, ICSM managing director Ian Carrotte is concerned that printers are still risking their livelihoods by dealing with businesses they are not familiar with.
He said: "We are worried that businesses are still opening themselves up to a bed debt when simple steps can be taken to avoid it. While the write-offs were lower in March, they consisted of a high number of lower value debts.
"This signifies the alarming number of companies being negatively impacted by poor-paying customers.
"Some companies can take these smaller hits on the nose and still be standing a few months down the lines but for others one or two of these punches could knock them completely out of the running."
Carrotte added that he expected the level of bad debt to continue to increase over the coming months.
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