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 Missouri, as in all states, a proof of claim is a formal statement that creditors must file to assert their right to receive a payment from a debtor's bankruptcy estate. This document is required in Chapter 7 (liquidation), Chapter 12 (adjustment of debts of a family farmer or fisherman), and Chapter 13 (individual debt adjustment) bankruptcy cases, provided there are assets available to distribute. The proof of claim form, which is provided by the bankruptcy court, requires creditors to indicate the nature of their claim (secured or unsecured), its priority status, and the claim's amount. Secured claims are backed by collateral, while unsecured claims are not. Priority claims, such as certain taxes and wages, are paid before nonpriority claims. Creditors must file the proof of claim by a specified deadline, which is set by the bankruptcy court, to participate in any distribution from the bankruptcy estate. In no-asset Chapter 7 cases, where the debtor has no assets to distribute, creditors are not required to file proofs of claim because there will be no distribution.