Bank Transactions Categorized as Expenses but not matched to open payables

Hello, I am starting to look into some transactions that have occurred for a company. They have open invoices for vendors and then some payments were made via wire or ach therefore paid directly through their bank. The prior bookkeeper would categorize those charges from the bank as expenses and not match them to the open invoices. Is there a way to fix this now? I just do not want to mess up their books as some are in prior years at this point.