My business is a single member LLC, and I file a schedule C the same as a sole proprietor. I recently setup a Solo 401k. I know that TurboTax will handle the contributions vs employee deferral. I'm not sure how to record the money leaving my checking account. I'm thinking I should record it as equity:member draw - the same as my paychecks since the amount of business contributions are going to be connected to profit. I can organize it into some some accounts to keep it clear. I don't think I want to make it an expense or that would mess up the business profit. I guess I'm really talking about recording profit sharing... even though it's with the sole prop.
