Four years after the government adopted rules meant to strengthen the reporting requirements for lobbyists and lend transparency to their contacts with lawmakers, most are making a good-faith effort to comply with the spirit of the law, according to an annual report released by the Government Accountability Office.

The yearly audit has been conducted by the government watchdog agency since the passage of the Honest Leadership and Open Government Act of 2007 in the wake of the Jack Abramoff scandal. It requires lobbyists to register, file quarterly updates and report their political contributions. The agency tracks how closely lobbyists are complying with the law and whether it is being enforced by the U.S. Attorney’s Office for the District of Columbia.

Of the income and expense filings reviewed at random, 97 percent of the lobbyists questioned could provide documentation that supported their filing and the GAO estimates that this backup information showed that 68 percent had filed accurate reports. Of those who didn’t, a significant chunk was due to rounding and other mathematical errors and most who were notified said they would file amended reports. Only about 2 percent failed to disclose required political contributions when cross referenced against data kept by the Federal Election Commission.

A focus of criticism in past audits was the lack of action taken by the U.S. Attorney’s Office once offenses were referred from the Senate and the House of Representatives, but the GAO said that efforts improved during the period in which it conducted the review. Of the 1,597 letters sent out to offenders in 2008 and 2009, 758 are now compliant with the law. The attorney’s office has also increased its staff designated to review lobbying compliance issues from six to 17 and implemented a system to track the status of enforcement actions, which the GAO had recommended in its last report.

“There seems to have been a marked increase in the number of letters the U.S. Attorney’s Office has sent out,” said Elliot S. Berke, an attorney with McGuireWoods.

Some attorneys caution that the audit does not provide a full picture into lobbying activity, as it only reviews those who register and file updates in accordance with the law. While it would be unusual for most lobbyists, who often work out of well-known shops and represent multiple clients, to evade the registration requirements, other individuals with less-transparent objectives spend time at agencies, visit the White House and check in with lawmakers on Capitol Hill. There is no formal system in place to track the actions of these pseudo lobbyists, unless someone happens to notice that a name on a visitor’s log isn’t in the registration database.

“That’s the way something would get triggered about somebody doing something that looks like lobbying — someone says, ‘That person should register,’ ” said Jan W. Baran of Wiley Rein.

In fact the GAO reports that actual penalties for violating lobbying disclosure laws are rare. Since the Lobbying Disclosure Act was passed in 1995 — that law was then updated by the 2007 reforms — the U.S. Attorney’s Office has only settled with three lobbyists and collected civil penalties of only $47,000. All three cases involved individuals who had failed to file. Though a possible recourse, criminal prosecutions are nonexistent.

“My sense of where the Congress is on this is that they are most concerned about ensuring the robustness of disclosure and improving it and making sure the information gets into the system,” said David Frulla, an attorney with Kelley Drye & Warren.