The Self-Directed Solo 401(k) allows for loans. The loan option will enable you to borrow from your retirement funds up to 50% of the plan value or $50,000, whichever is less. Solo 401(k) holders may use loans to pay off personal debt, fund a business, or use as the holder sees fit. If you want to take a loan from your 401(k), fill out the loan application provided on your online Dashboard.