61(1)Notwithstanding any provisions of this Part respecting estimates or payrolls and notice to employers, an employer shall, without demand from the Commission, cause to be paid to the Commission the full amount of every assessment assessed or levied in accordance with this Part in respect to workers in his employ who are entitled to compensation hereunder, and every assessment, whether the employer has notice thereof or otherwise, is a debt unliquidated until the amount thereof is ascertained by adjustment as provided by this Act and payable by the employer to the Commission.