(a) Agencies shall establish internal controls to ensure that the use of the CSC account by the agency or other authorized activities is limited to the purchase of items for official Government use. The controls shall include written instructions that contain a statement prohibiting the use of the CSC account in acquiring items for other than Government use. When an agency makes a purchase of more than $500 per line item from a GSA customer supply center which is other than a similar lowest priced item available from a multiple-award schedule, GSA will assume that a justification has been prepared and made a part of the buying agency's purchase file. Availability of products, regardless of the total amount of the line item price, does not relieve an agency of the responsibility to select the lowest priced item commensurate with needs of the agency.

(b) Office supplies needed by Members of Congress and the Delegate of the District of Columbia for use in their offices in the House or Senate Office Buildings should be obtained from the Senate and Houses Representatives supply rooms, as appropriate. Members of Congress, except for the Delegate of the District of Columbia, should limit their use of the CSCs to those located outside of the District of Columbia. The Delegate of the District of Columbia may obtain office supplies for the use of his or her district offices from the CSC serving the District of Columbia.