A more thorough explanation:

Proof of claim is a written statement submitted by a creditor in a bankruptcy case to show the basis and amount of their claim.

For example, if a person owes money to a credit card company and files for bankruptcy, the credit card company can submit a proof of claim to the bankruptcy court to show how much money the person owes them.

Pl. proofs of claim.

• A hospital submits a proof of claim to a bankruptcy court to show how much money a patient owes for medical treatment.
• A landlord submits a proof of claim to a bankruptcy court to show how much rent a tenant owes.
• A supplier submits a proof of claim to a bankruptcy court to show how much money a business owes for goods or services.

These examples illustrate how different types of creditors can submit a proof of claim to a bankruptcy court to show the amount of money they are owed.