I am a therapist and have a sole proprietor practice and put my funds into a SEP IRA, a portion of which funded my SDIRA many years ago... 

@Colin Murphy First of all let me say that you are ahead of the curve as far as our knowledge. many people here talk about whether they should start a "company" not realizing that they are a company, it is just s sole proprietor. 

Are you a Sole Proprietor. 

A sole proprietor can also set up solo 401k without a W2 income or 1099. 

Go with "proprietor" and "renter."

Hello everyone, my wife and I are just starting out and we were hoping for some guidance on an issue.Basically we are trying to fill out a W-9 and aren't sure if we should be a "sole proprietor" or a "partnership."

the only additional tax deduction available to an LLC that isn’t available to a sole proprietor is the fees an LLC must pay.  

This is from a Tax Attorney's website (not my attorney's someone else"Layman’s version of Deduction for Qualified Business Income of an Individual under Sec. 199AThe Qualified Business Income tax deduction gives the owners of pass-through businesses like sole proprietors, partnerships, S corporations and real estate investors a deduction equal to 20% of qualified business income.What is Qualified Business Income?

(not tax advice just what I've been told to do by my cpa in Louisiana)I am the sole proprietor so moving money from my personal account to my business account and back and forth is OK since it's all traceable.

@John Madepending on the level of activity with this entity you might consider just setting up as a Sole Proprietor and file a simple Schedule C.