Filing Chapter 13 means that your creditors must file a proof of claim in order to be repaid under the Chapter 13 repayment plan. The proof of claim does not guarantee that their debt will be repaid under the plan, but failure to file means their debt will certainly not be repaid. However, there are special circumstances in which you may wish to file proof of claim on behalf of your creditors when filing Chapter 13.
When to File
It is very important that any and all nondischargeable debts be listed with filed proofs of claim in your Chapter 13 case. Nondischargeable debts will not be forgiven in the Chapter 13 discharge process, so if they are not filed as proofs of claim, they will not become part of the repayment plan, and will therefore still be listed as outstanding debts with the potential to go into default and collections, even while you are in the midst of your Chapter 13 repayment plan. Therefore it is highly advisable to file proofs of claim on behalf of any and all holders of nondischargeable debt against you. Nondischargeable debt, includes most tax debt, student loan debt, and child support or alimony owed.
In the case of secured debts, it is possible that the debt will not be included in the Chapter 13 repayment even though the secured debtor is not required to file a proof of claim; in order to be thorough and ensure that your secured debt does not go into default or collection during the course of your Chapter 13 repayment, it is advisable to file a proof of claim on behalf of your secured creditors.