What is indicated when the average age of accounts receivable for a firm is 45 days, but credit terms require customers to pay accounts within 30 days? ‘A uniform system of accounts, including...

What is indicated when the average age of accounts receivable for a firm is 45 days, but credit terms require customers to pay accounts within 30 days? ‘A uniform system of accounts, including identical forms for balance sheets and income statements is a prerequisite of inter-firm comparisons.’ Elucidate.