employing unit for which services are customarily performed by such individual in more than one State shall be deemed to be services performed entirely within any one of the States or Canada (1) in which any part of such individual’s service is performed or (2) in which such individual has his residence or (3) in which the employing unit maintains a place of business.

the unemployment compensation laws of one or more States or Canada 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 Director finds will be fair and reasonable as to all affected interests and will not result in any substantial loss to the State’s account in the unemployment trust fund.

compensation law of another State or Canada or of the Federal Government, shall be deemed to be wages for insured work for the purpose of determining an individual’s rights to benefits under this Act, and wages for insured work shall be deemed to be wages or employment on the basis of which unemployment compensation under such law of another State or Canada or of the Federal Government is payable, but no such arrangement shall be entered into unless it contains provisions for reimbursements to this State’s account in the unemployment trust fund for such of the benefits paid under this Act upon the basis of such wages or employment, and provisions for reimbursements therefrom for such of the compensation paid under such other law upon the basis of wages for insured work, as the Director finds will be fair and reasonable as to all affected interests.

wages for insured work shall for the purposes of Section 1401 of this Act be deemed to have been paid to the Director 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 such reimbursement to this State’s account in the unemployment trust fund of such contributions and the actual earnings thereon as the Director finds will be fair and reasonable as to all affected interests.

due and owing to any Federal agency or any State by an employing unit, and erroneously paid to this State, may be repaid or transferred to such agency or State, and contributions, interest, and penalties properly due and owing to this State by an employing unit and erroneously paid to any Federal agency or any State may be repaid or transferred to this State. In the event that the State or the Federal agency to which such contributions were erroneously paid has paid benefits based in whole or in part on the wages on which such contributions were paid, such arrangements may provide that such Federal agency or State may deduct such an amount of such benefits paid as the parties to the arrangement shall find is just and equitable, from the contributions, interest, and penalties to be repaid or transferred. In the event that the amount of such benefits, as so found, exceeds the amount of contributions, interest, and penalties erroneously paid, the arrangements may provide for reimbursement of such excess by the Federal agency or State to which such contributions, interest, and penalties should have been paid. Arrangements entered into prior to July 1, 1945, which comply with the provisions of this subsection are hereby validated to the same extent as if they had been entered into on or after July 1, 1945.

Section, the Director shall participate in any arrangements for the payment of benefits on the basis of combining an individual’s wages and employment under this Act with his wages and employment under the unemployment compensation laws of other States or Canada, which are approved by the United States Secretary of Labor or other appropriate Federal agency in consultation with the State unemployment compensation agencies as reasonably calculated to assure the prompt and full payment of benefits in such situations, and which include provisions for (1) applying the base period specified in a single State law to a claim involving the combining of an individual’s wages and employment subject to two or more State unemployment compensation laws; and (2) avoiding the duplicate use of wages and employment by reason of such combining.