When it is in a state of actual insolvency and the legal two-month period has passed since the company became aware, or should have become aware, of that situation.
Yes. The law allows the debtor to notify the court of the opening of negotiations with creditors in order to attempt a restructuring plan when there is a likelihood of insolvency or imminent insolvency.
Yes. A creditor may file for bankruptcy proceedings if they provide evidence of their claim and base the request on external facts indicating insolvency.