Uniform Lobbying Cost Principles Act of 1984

Uniform Lobbying Cost Principles Act of 1984 - Prohibits any commercial or nonprofit organization from allocating the cost of influencing legislation to: (1) a Federal or federally assisted grant or cooperative agreement, other than a block grant; or (2) a contract with a Federal agency, other than a competitive firm fixed price contract. Permits a State to: (1) waive the application of this Act to communications that would constitute the influencing of State legislation; and (2) promulgate uniform rules for allocating the cost of influencing State legislation under federally assisted grants or cooperative agreements administered by such State.

Requires an organization to notify a Member of Congress of the actual or estimated costs of providing technical advice or assistance to such Member and of the specific grant, agreement, or contract to which such costs will be allocated when such costs exceed $100, except with respect to activity specifically authorized by Congress. Permits an organization, in lieu of specifying costs allocated to more than one grant, contract, or agreement, to provide an estimate of the percentage of the organization's total revenues derived from Federal or federally assisted grants, contracts, or agreements.

Requires the Director of the Office of Management and Budget, after consulting with Federal agencies, commercial and nonprofit organizations, and Congress, to promulgate uniform guidelines to carry out this Act.