(a) Services performed by an individual for a single employer for which services are customarily performed in more than one state shall be deemed to be services performed entirely within any one of the states (i) in which any part of such individual's service is performed, or (ii) in which such individual has his residence, or (iii) in which the employer maintains a place of business, provided there is in effect as to such services an election approved by the agency charged with the administration of such state's unemployment compensation law pursuant to which all the services performed by such individual for such employer are deemed to be performed entirely within such state.

(b) Potential rights to benefits accumulated under the unemployment compensation laws of one or more states or under one or more such laws of the Federal Government, or both, may constitute the basis for the payment of benefits through a single appropriate agency under terms which the department finds will be fair and reasonable as to all affected interests and will not result in any substantial loss to the fund.

(c) Wages or services upon the basis of which an individual may become entitled to benefits under an unemployment compensation law of another state or of the Federal Government shall be deemed to be wages for employment for the purpose of determining his rights to benefits under this act, and wages for employment as defined in this act on the basis of which an individual may become entitled to benefits under this act shall be deemed to be wages or services on the basis of which unemployment compensation under such law of another state or of the Federal Government is payable, but no such arrangement shall be entered into unless it contains provisions for reimbursements from the fund for such of the compensation paid under such other law upon the basis of wages for employment as defined in this act as the department finds will be fair and reasonable as to all affected interests.

(d) Contributions due under this act with respect to wages for employment shall, for the purpose of section three hundred one of this act,¹ be deemed to have been paid to the fund as of the date payment was made as contributions therefor under another state or Federal unemployment compensation law, but no such arrangement shall be entered into unless it contains provisions for reimbursement to the fund of such contributions, or an amount equal to such contributions, less any benefits which may have been paid by such other state, based upon such contributions. Such arrangement may provide for the transfer of interest earned on such contributions while credited to the state to which they were erroneously paid.

Reimbursements paid from the fund pursuant to paragraph (c) of this section shall be deemed to be benefits for all the purposes of this act. The department is authorized to make to other state or Federal agencies and to receive from such other state or Federal agencies reimbursements from or to the fund in accordance with arrangements entered into pursuant to this section.

The administration of this act and of other state and Federal unemployment compensation and public employment service laws will be promoted by cooperation between this State and such other states and the appropriate Federal agencies in exchanging services and making available facilities and information. The department is, therefore, authorized to make such investigations, secure and transmit such information, make available such services and facilities and exercise such of the other powers provided herein with respect to the administration of this act as it deems necessary or appropriate to facilitate the administration of any such unemployment compensation or public employment service law and in like manner to accept and utilize information services and facilities made available to this State by the agency charged with the administration of any such other unemployment compensation or public employment service law.

To the extent permissible under the laws and Constitution of the United States, the department is authorized to enter into or cooperate in arrangements whereby facilities and services provided under this act and facilities and services provided under the unemployment compensation law of any foreign government may be utilized for the taking of claims and the payment of benefits under the employment security law of this State or under a similar law of such government; and

(e) Services performed on vessels engaged in interstate or foreign commerce for a single employer, wherever performed, shall be deemed to be performed within this State or within such other states.

(f) The secretary shall participate in any arrangements for the payment of compensation on the basis of combining an individual's wages and employment covered under this act with his wages and employment covered under the unemployment compensation laws of other states which are approved by the United States Secretary of Labor in consultation with the State unemployment compensation agencies as reasonably calculated to assure the prompt and full payment of compensation in such situations and which include provisions for:

(g) Overpayments of compensation under this act shall be deducted from compensation payable under an unemployment benefit program of the United States or another state, and overpayments of compensation under an unemployment benefit program of the United States or another state shall be deducted from compensation payable under this act or compensation paid by the Commonwealth pursuant to an unemployment benefit program of the United States. A reciprocal agreement under this subsection shall be consistent with the requirements of section 303(g) of the Social Security Act (49 Stat. 620, 42 U.S.C. § 301 et seq.) and the regulations and instructions of the United States Department of Labor.