I have a part-time job consulting that gives me a few hundred bucks each month so I am thinking of opening a solo 401k to rollover my existing traditional IRAs. I understand that I will have to sign up for an EIN and then make my consulting job as a sole proprietorship, which I would report when I file my personal taxes with the relevant tax schedules and SE forms (that TurboTax would generate).

1. I already get a 1099 for this consulting work, and I guess I am confused with how I would report it as a sole proprietorship come tax time? Would I indicate in TurboTax that the 1099 belongs to the proprietorship so it gets attached to the right forms, and not the portion with my W2s and such?

2. I get a 1099 from the client under my social security number. If I get an EIN to create my self-employed proprietorship, would I tell my client to report the 1099 using the EIN or still keep my SSN in the 1099? Or is the SSN good for the 1099 (so no change with the client), and the EIN only applies for TurboTax to fill out the relevant self-proprietor forms?

3. As long as I am a consultant, I can contribute to my solo 401k (in addition to using it for rollovers from traditional IRAs if needed). After I stop this consulting job on the side, I assume that I can keep the solo 401k open and use it only for rollovers, but I would not be able to contribute to the 401k because my consulting income has ceased. Is this right?

4. After I stop this consulting job, do I keep the EIN open/active or do I have to close/cancel it? Would there be anything special I need to tell the IRS or do when filling out my taxes (with TurboTax) to say that the “business” stopped? Or just by telling TurboTax when I fill out my taxes that there is no self-proprietorship business anymore, and then it just does not generate the SE forms/schedules and that is what tells the IRS that I am no longer engaged in that (even though I would keep the solo 401k open)?

Thank you!