Proof of Debts Rules

Where a creditor has so valued his security, he may at any time amend the valuation
            and proof on showing to the satisfaction of the trustee or the court that the valuation
            and proof were made bona fide on a mistaken estimate or that the security has diminished
            or increased in value since its previous valuation, but every such amendment shall be
            made at the cost of the creditor and upon such terms as the court shall order, unless
            the trustee allows the amendment without application to the court.