For each fiscal year (beginning with the fiscal year which ends ) there is authorized to be expended from the contingent fund of the Senate such amount as necessary for the Conference of the Majority and an equal amount for the Conference of the Minority. Payments under this section shall be made only for expenses actually incurred by such a Conference in carrying out its functions, and shall be made upon certification and documentation of the expenses involved, by the Chairman of the Conference claiming payment hereunder and upon vouchers approved by such Chairman and by the Committee on Rules and Administration, except that vouchers shall not be required for payment of long-distance telephone calls.