2016 Lobbying Disclosure: Observations on Lobbyists’ Compliance with Disclosure Requirements, GAO-17-385: Published: Mar 31, 2017. Publicly Released: Mar 31, 2017.

“Lobbyists must register with the Secretary of the Senate and the Clerk of the House when they take on new clients, and file reports disclosing their lobbying activities, income, and certain political contributions. In our most recent review of compliance with these requirements, we found that

• 90% of lobbyists filed new client reports,
• 83% could provide documentation for income, and
• 94% filed political contributions reports.

We also found that some lobbyists were unclear about the need to disclose certain previous jobs—including certain executive agency positions. These findings are generally consistent with our prior reports on the subject.”