Last month, a mid-sized general contractor in Houston paid their concrete supplier twice. $18,000 disappeared before accounting caught the error. It wasn't a one-time mistake. Duplicate payments cost construction companies an average of $900 to $2,500 every single month. For a typical contractor processing 200–300 invoices monthly, that's $10,800 to $30,000 in lost profit annually. Here's why you should care: Unlike other business expenses you can control, duplicate payments