A new US law requires all corporations and LLCs to file a "BOI report" containing information about the company's "beneficial owners" by January 1. It's a one-time filing, but a new filing must be made within 30 days of any change (e.g. an owner moves).
The penalties for non-compliance are steep: $500/day fines, and up to 2 years in prison. I'm not sure how small businesses are expected to learn about this; I had not heard about it until my accountant emailed me.
Here's the link to file the report: https://boiefiling.fincen.gov/
More information about the law: https://home.treasury.gov/news/press-releases/jy2015