As a general rule, no.  The Federal government must have specific statutory authority to retain fees from outside sources.  There is no Department-wide authority to retain fees; however, individual bureaus may have authorities, specific to them, which authorize them to collect and retain fees.  For example, the International Trade Administration and the Bureau of Industry and Security have the Mutual Educational and Cultural Exchange Act of 1971 (MECEA).  Contact the General Law Division for more information.

To the extent that we do charge an attendance fee without statutory authority, the fee would be considered a user fee under 31 U.S.C. § 9701 and would have to be deposited into the General Fund of the Treasury pursuant to the Miscellaneous Receipts Act.  31 U.S.C. § 3302(b). 

Note that a contractor may charge a convenience fee as part of a no-cost element of a contract for conference services.  The convenience fee is not technically an attendance fee, but rather an expense the attendee is voluntarily paying in order to obtain services that the Department does not consider an integral part of the conference.  As such, the fees are not received “for the Government” but rather collected by the contractor for its own use. 
 

No.  Exhibitor fees are the same as attendance fees, see # 1, above.