Bankruptcy courts grant a filing fee waiver based on the specific information about the filer’s income, expenses and assets disclosed in the fee waiver application.
If the court later learns that - all things considered - the fee waiver should not have been granted, the court has the ability to revoke it and order the filer to pay the full fee. Usually, the trustee discovers this type of information by the time of the 341 meeting.
The court will provide payment instructions on how and by when to pay the full filing fee in the order revoking the waiver. To avoid a dismissal of your case, make sure to follow the instructions and pay the fee as soon as possible.