Whether you can file a civil lawsuit against someone who has filed bankruptcy is a complex question with more than one answer. Standard procedure is that per federal law, any collection efforts must cease when someone files bankruptcy. Trying to collect a debt after being notified the debtor is filing bankruptcy can actually result in criminal penalties under federal law.
Those who are considering filing bankruptcy must file a document called "Suggestion of Bankruptcy" with the bankruptcy court. Based on this information, you cannot file a civil lawsuit after you receive this notification that a debtor plans to file bankruptcy. Filing this document gives debtors what is called an automatic stay from collection efforts. Even if you started the civil suit before the debtor filed the Suggestion of Bankruptcy, you must stop any further court proceedings regarding the suit.
If a creditor can prove the debt was obtained by fraud or false pretenses, the debt is not dischargeable in bankruptcy court. Non dischargeable means the debt will not be forgiven. The debtor will still be responsible to pay. If you think your case meets these criteria you can file what is called an Adversary Proceeding in bankruptcy court.
Other examples of debt that cannot be discharged include student loans and money owed to state or federal agencies. Examples of debts to agencies include federal fines, back ordered child support or alimony, and back taxes.
Creditors may file a request for relief from the automatic stay so that the creditor can continue pursuing the case. This request is filed in the same district court where the civil suit began. It is up to the district court to approve or deny the creditor's request.
The best way to prove your claim is to file an Adversary Proceeding. Doing so states that your claim is valid, has priority over other claims, or is secured by real property.
If creditors do nothing to assert their claim, the claim will be dismissed when the bankruptcy is approved. By not asserting a claim, you are telling the defendant and the bankruptcy court that you are waiving your right to pursue payment.
It is advisable to consult with or retain an attorney when faced with a debtor who is filing bankruptcy. Doing so avoids violating any federal law that protects the debtor's rights.