On December 1, 2011, a revised Official Bankruptcy Form 10 became effective. Form 10 now clarifies that all creditors must attach copies of the actual documents evidencing the existence of their claims to the proof of claim (such as a promissory note evidencing a lender's claim). Secured creditors must also attach evidence of perfection of the security interest securing their claim (such as a financing statement, mortgage or certificate of title). It is not clear what consequences secured creditors may face if they fail to provide these documents.

Form 10 was previously unclear on whether a summary of the documents was sufficient, so it was revised to be consistent with Federal Rules of Bankruptcy Procedure 3001(c) and 3001(d) to require copies of actual documents. Form 10 states that a creditor also has the option of including a summary in addition to the documents. If the documents are not available, Form 10 requires the creditor to explain why.

To learn more about proofs of claim, see Practice Note, Filing a Proof of Claim in a Chapter 11 Bankruptcy Case.