One of the more common questions debtors encounter is what to do when they discover a bill that was incurred before they filed their case, but their case has already been filed. Their first instinct is that any efforts at including the bill are moot because the case has been filed, until they discover that they can simply amend the appropriate bankruptcy schedule.
Amending a bankruptcy schedule is easy; it requires the information that the debtor needs to add, the schedules to be amended as a whole, and a signed declaration for documents filed after the bankruptcy petition was filed. In most cases, there is no fee required. This includes times where you are updating basic forms or schedules of the petition, such as Schedule A for any real estate or Schedule B for personal property. There are times where the court charges a nominal fee, however, like when you amend schedules that include your debts, like Schedule D for secured debt or Schedule F for unsecured debt.
In a Chapter 13, the amendment of a schedule that lists debts, in addition to costing the nominal court charge, requires a further filing of a modified Chapter 13 plan that provides for payment, for whatever percentage that is being paid under the plan, for the new creditor. This will usually result in a higher trustee payment than originally anticipated If the creditor comes in later in the case, a motion to modify the plan may be required as well.
Regardless, in all cases you want to try and avoid having to amend the petition in the first place by having all of your information, documents, and bills in order to give to your attorney before filing the case. If you do need to amend, however, don't hesitate to contact your bankruptcy attorney to ensure it is done correctly, in an orderly fashion, and in accordance with local and national bankruptcy rules.