A Creditor’s Matrix (also known as a mailing matrix or “List of Creditors”) is an alphabetical list of the names and addresses of all your creditors and any co-debtors that you have listed on Schedule D (link is external) and Schedule E/F (link is external). The Matrix must be filed at the same time the bankruptcy petition is submitted to the Court – even if your creditors are already documented in the other forms that accompany your petition.