6. Where a person with care with respect to whom a maintenance assessment has been made believes that, by virtue of section 44 or 55 of, or paragraph 16 of Schedule 1 to, the Act, the assessment has ceased to have effect or should be cancelled, she shall, as soon as is reasonably practicable, inform the Secretary of State of that belief, and of the reasons for it, and shall provide such other information as the Secretary of State may reasonably require, with a view to assisting the Secretary of State or a child support officer in determining whether the assessment has ceased to have effect, or should be cancelled.