(1) It shall be the duty of the president and secretary or other executive officer or officers having power to levy assessments, of each and every mutual insurance company doing business in this state under authority of this chapter to levy an assessment on the members according to classification thereof, sufficient to cover all liability of the company at each and every assessment: Provided, however, That the commissioner may if he deems it advisable grant authority to carry forward a portion of any deficit. Any deficit carried over must be included in the assessment levied during the year immediately following.

    (2) It shall be unlawful for any mutual fire insurance company incorporated under the provisions of section 6804 (farmers’ mutuals) to conduct its business on the delayed assessment plan and authority is hereby given for mutual insurance companies incorporated under this chapter to collect an advance premium ratably assessed against the membership of an amount which shall be estimated as sufficient to pay each member’s proportionate share of the losses and expenses of the company for the ensuing 12 months or lesser period as prescribed by the articles of incorporation of the company, and to provide for surplus funds as permitted in section 6844.

    (3) The amount of membership fee collected per $100.00 of insurance by a mutual insurance company incorporated under the provisions of this chapter at the time of issuing a policy for a new member or increasing a policy shall be uniform for all companies on the same class of business and shall be prescribed by the commissioner upon agreement on the amount of such membership fee by a majority of the companies writing each separate class. Such fee shall be the only fee collected in addition to the advance premium. No new membership fee shall be charged for a policy reinstated within 6 months of the date such policy was cancelled: Provided further, That any mutual fire insurance company doing business in this state under authority of this chapter and operating upon the advance premium plan while having a surplus at least equal to $200,000.00 may issue an insurance policy which shall provide that the member insured shall not be liable for an additional assessment during the period for which an advance premium has been paid, and in no event shall the holder of any such policy be liable to the company for a greater amount than the advance premium charged for that period.