I am a sole proprietor who also has a day job.

To enable my spouse to participate in my Solo 401k plan, I am planning to file as a Qualified Joint Venture for the first time this year. My spouse consistently helps with bookkeeping and IT and we meet material participation requirements.

Since this is the first time we are filing this way, I am looking at what respective percentage ownership of the business gives us the best tax and contribution outcome this year. I keep landing on a 67%-33% split.

IRS says for QJV, “The spouses must share the items of income, gain, loss, deduction, and credit in accordance with each spouse’s interest in the business.” But it doesn’t say how that interest is determined.

Two questions:

1. Can I make the split something other than 50/50 for a QJV in a community property state (California)? The business existed before we were married.
2. If yes and I make the split 67-33 this year, do I need to do it that way every year, or could I change it to 80-20 or 70-30 or something else in future years, depending on tax and contribution scenarios?

I’ve seen this discussed here and there, but have yet to find a definitive answer on these two points.

Thanks in advance.