Legal Question in Business Law in California

You may, depending on what you've filed already. You also need to be careful to ensure your disclosure documents properly reflect the change, and the terms of the disassociation should be in writing, signed.

The departure of a co-owner is such a fundamental change in a business that all regulatory filings, proposed filings and private disclosure documents need to be reviewed for continued accuracy. Also, probably, the events that led up to a co-founder pulling out need to be discussed in some detail.

Also, I'm unclear as to what law, regulation or rule prompts filing documents with the SEC in the first place. Most private placements, not necessarily all, have as a purpose the avoidance of the need to register with the SEC, in reliance upon some recognized exemption from the registration requirements.

Finally, any firm doing financings that require SEC filings should be represented by a lawyer or law firm that is able to answer questions of this sort. Securities law is unforgiving and civil and criminal penalties may await those who make even seemingly slight mistakes, and a do-it-yourself approach is highly risky.