What should a company with an informal past actually do?

A sudden, unexplained jump in declared figures is itself a red flag; trying to clean up the past overnight is not the answer. The right approach is to separate the risks by their nature — under-declaration and false-document risk are legally very different — then build a record-keeping discipline that matches real transactions from today onwards, and address the past through available legal mechanisms, well before a credit application or a partnership discussion arises.