FARA requires so-called foreign agents to register within 10 days of agreeing to conduct work for the foreign entity and to provide updates every six months on political activities. The disclosures require more minute details than what is covered for domestic lobbyists.
For instance, foreign agents must disclose efforts to exert politically-related influence on think tanks and through the media, as well as to directly lobby government officials.
Deliberately failing to file as a foreign agent may result in a felony criminal charge accompanied by steep monetary civil penalties. In practice, however, the Department of Justice generally encourages voluntary compliance and prosecutions under the act are quite rare, said Joseph Sandler, an attorney who specializes in political law, including FARA. The Justice Department generally allows people to register retroactively if questions arise about their past activities and the law requires no late fees or other penalties.
If it was genuinely inadvertent or negligent, if theres nothing nefarious you want to hide, theres no downside to retroactively registering, Sandler said.