43 Pa. Stat. § 909
Two or more employers that have become liable for payments in lieu of contributions, in accordance with the provisions of section 1104 of this act, may file a joint application with 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 application shall identify and authorize a group representative to act as the group's agent for the purposes 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 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 services 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 section, 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 section by members of the group and the time and manner of such payments.
43 P.S. § 909