Each employer that is liable for payment in lieu of contributions shall pay the department for the fund an amount equal to the amount of regular benefits and one-half the extended benefits paid that are attributable to service in the employ of such employer except that after January 1, 1979, the State or any political subdivision or any instrumentality thereof as defined in § 41-27-230(2)(b) shall be required to reimburse the full amount of regular and extended benefits attributable to service in its employment. If benefits paid to an individual are based on wages paid by more than one employer and one or more of such employers are liable for payments in lieu of contributions, the amount payable to the fund by each employer that is liable for such payments shall be determined in accordance with the provisions of subsection (1) or (2).

(1) If the benefits paid to an individual are based both on base period wages paid by one or more employers that are liable for contributions and on base period wages paid by one or more employers that are liable for payments in lieu of contributions, the amount payable by each employer that is liable for payments in lieu of contributions shall bear the same ratio to the sum of the amounts payable by such employers as the total base period wages paid to the individual by each employer that is liable for payments in lieu of contributions bear to the total base period wages paid to the individual by all such employers.

(2) If benefits paid to an individual are based on wages paid by two or more employers that are liable for payments in lieu of contributions, the amount of benefits payable by each such employer shall be an amount which bears the same ratio to the total benefits paid to the individual as the total base period wages paid to the individual by such employer bear to the total base period wages paid to the individual by all of his base period employer.

(3) Two or more employers that have been liable for payments in lieu of contributions, in accordance with the provisions of § 41-31-620 may file a joint application to the department for the establishment of a group account for the purpose of sharing the cost of benefits paid that are attributable to service in the employ of such employers. Each such application shall identify and authorize a group representative to act as the group’s agent for the purpose of this section. Upon its approval of the application, the department shall establish a group account for such employers effective as of the beginning of the calendar quarter in which it receives the application and shall notify the group’s representative of the effective date of the account. Such account shall remain in effect for not less than two calendar years and thereafter until terminated at the discretion of the department or upon application by the group. Upon establishment of the account, each member of the group shall be liable for payments in lieu of contributions with respect to each calendar quarter in the amount that bears the same ratio to the total benefits paid in such quarter that are attributable to service performed in the employ of all members of the group as the total wages paid for service in employment by such member in such quarter bear to the total wages paid during such quarter for service performed in the employ of all members of the group. The department shall prescribe such regulations as it deems necessary with respect to applications for establishment, maintenance, and termination of group accounts that are authorized by this subsection, for addition of new members to, and withdrawal of active members from such accounts, and for the determination of the amounts that are payable under this subsection by members of the group and the time and manner of such payments.