The deadline to file a proof of claim against a debtor in bankruptcy. The debtor must serve all known creditors with notice of the bar date. From the creditor's perspective, the bar date is one of the most critical dates in the bankruptcy case. A creditor should file the proof of claim as far in advance as possible of the bar date to give it the most flexibility to correct any irregularities.

For more information, see Practice Note, Filing a Proof of Claim in a Chapter 11 Bankruptcy Case.