2 U.S.C. § 1610: Estimates based on tax reporting system

make a good faith estimate (by category of dollar value) of applicable amounts that would be required to be disclosed under such section for the appropriate quarterly period to meet the requirements of sections 1603(a)(3) and 1604(b)(4) of this title; and lobbying contacts with covered legislative branch officials (as defined in section 1602(4) of this title ) and lobbying activities in support of such contacts; and lobbying of Federal executive branch officials to the extent that such activities are influencing legislation as defined in section 4911(d) of title 26 . make a good faith estimate (by category of dollar value) of applicable amounts that would not be deductible pursuant to such section for the appropriate quarterly period to meet the requirements of sections 1603(a)(3) and 1604(b)(4) of this title; and lobbying contacts with covered legislative branch officials (as defined in section 1602(4) of this title ) and lobbying activities in support of such contacts; and lobbying of Federal executive branch officials to the extent that amounts paid or costs incurred in connection with such activities are not deductible pursuant to section 162(e) of title 26 . inform the Secretary of the Senate and the Clerk of the House of Representatives that the registrant has elected to make its estimates under such procedures; and make all such estimates, in a given calendar year, under such procedures. the differences between the definition of “lobbying activities” in section 1602(7) of this title and the definitions of “lobbying expenditures”, “influencing legislation”, and related terms in sections 162(e) and 4911 of title 26, as each are implemented by regulations; the impact that any such differences may have on filing and reporting under this chapter pursuant to this subsection; and any changes to this chapter or to the appropriate sections of title 26 that the Comptroller General may recommend to harmonize the definitions.