State agencies may provide for the advancing of funds as herein provided to defray the charges mentioned in Section 11256. Any state agency may, and upon order of the Director of General Services shall, authorize such advances from any fund or appropriation available to it for payment for work, services, materials, or equipment to the fund or appropriation of the state agency which is to perform such work or render such services or furnish any materials or equipment to it, an amount equal to the estimated charges therefor or in an amount determined by the Director of General Services, and the State Controller shall transfer any amounts so authorized or
determined.