As part of your Chapter 13 plan, you will submit to the court a proposed amount that you will pay towards your unsecured debt (usually credit cards) on a monthly basis. Payments of the unsecured debts will be based on how "allowed claims" that are filed by the creditors. All creditors with allowed claims will be paid a share of the money that you are paying into the plan for unsecured creditors. Establishing an allowed claim is the only way a creditor can get paid any money in a Chapter 13 plan.
When you file a bankruptcy case, your creditors will receive notice of the filing. Unsecured creditors that want a share of the payments must file a "Proof of Claim." Once the creditor files the Proof of Claim, you or the trustee can object to the claim if you have a legal basis for doing so. For example, you can argue that you don't really owe the claim or that you owe less than what they are claiming. The bankruptcy code gives each claim a preliminary assumption of validity unless you object. You must have a valid reason for objecting under the bankruptcy code. If you object, the court will then decide which claims are allowed.
