(a) Audit
On an annual basis, the Comptroller General shall audit the extent of compliance or noncompliance with the requirements of this chapter by lobbyists, lobbying firms, and registrants through a random sampling of publicly available lobbying registrations and reports filed under this chapter during each calendar year.

(b) Reports to Congress

(1) Annual reports
Not later than April 1 of each year, the Comptroller General shall submit to the Congress a report on the review required by subsection (a) for the preceding calendar year. The report shall include the Comptroller General's assessment of the matters required to be emphasized by that subsection and any recommendations of the Comptroller General to—

(A) improve the compliance by lobbyists, lobbying firms, and registrants with the requirements of this chapter; and

(B) provide the Department of Justice with the resources and authorities needed for the effective enforcement of this chapter.

(2) Assessment of compliance
The annual report under paragraph (1) shall include an assessment of compliance by registrants with the requirements of section 1603(b)(3) of this title.

(c) Access to information
The Comptroller General may, in carrying out this section, request information from and access to any relevant documents from any person registered under paragraph (1) or (2) of section 1603(a) of this title and each employee who is listed as a lobbyist under section 1603(b)(6) of this title or section 1604(b)(2)(C) of this title if the material requested relates to the purposes of this section. The Comptroller General may request such person to submit in writing such information as the Comptroller General may prescribe. The Comptroller General may notify the Congress in writing if a person from whom information has been requested under this subsection refuses to comply with the request within 45 days after the request is made.