If the person is competent enough to be able to prepare their petition and testify about their financial affairs, then they can file directly.
In most jurisdictions, a person who holds a valid power of attorney can file a bankruptcy proceeding on behalf of an incompetent person. If there is no power of attorney, a court-appointed guardian or conservator can file.
Doing so would require the assistance of a highly experienced bankruptcy attorney, as these proceedings are rare and they would have to comply with current caselaw and statutory law requirements.
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