A proof of claim is the form document a creditor must complete to be paid from the assets of a bankruptcy case. The proof of claim generally tells the bankruptcy trustee whether the claim is secured or unsecured, priority or nonpriority, and the amount of the claim. All creditors who want to be paid from the bankruptcy estate must file a proof of claim in Chapter 7, 12, and 13 bankruptcy cases—except in Chapter 7 no-asset cases, as there are no funds for distribution to creditors.

In Illinois, as in all states, a proof of claim is a written statement that creditors must file with the bankruptcy court to assert their right to receive a distribution from the bankruptcy estate. This form outlines the nature of the claim (secured or unsecured), its priority status, and the claim amount. Creditors are required to file a proof of claim in Chapter 7 (liquidation), Chapter 12 (family farmer or fisherman reorganization), and Chapter 13 (individual debt adjustment) bankruptcy cases if they wish to participate in the distribution of the bankruptcy estate. However, in Chapter 7 cases where the trustee has determined there are no assets to distribute, creditors are not required to file proofs of claim because there will be no distribution. The requirement to file a proof of claim is governed by federal bankruptcy law, specifically under 11 U.S.C. § 501 and the Federal Rules of Bankruptcy Procedure. It is important for creditors to file the proof of claim by the deadline set by the bankruptcy court to preserve their rights to payment from the estate.