I’ve verified that the Solo 401k allows for after tax contributions and in plan conversions. Our plan document allows for both, however since this is a Solo plan we can fill out the 5500-EZ which is basically just a basic accounting of deposits, plan assets and number of employees so it can be self filed. The custodian will generate a 1099 R when we move funds from the After Tax 401k bucket to either the Roth 401k bucket or even roll out to the personal Roth IRA.

On our Schedule C we will report the Deductible contribution to the plan.
On our 1040 we report the 1099 R showing that the rollover is not taxable.

Is their any other reporting we need to do on the 5500, our Schedule C or our personal return?