Legal Question in Credit and Debt Law in Louisiana

Not if you disclose your agency (i.e., disclose to the lender that you are an agent acting on someone else's behalf) and so long as the loan is for the benefit of person who gave you the power of attorney, not your benefit or someone else's benefit. As an agent, you have what is called a "fiduciary duty" to always act in their best interests. Breaching that fiduciary by putting your interests or someone else's interest before theirs is actionable and illegal. Also, the power of attorney would have to grant you that authority to borrow money for them. Powers of attorney can be general or limited. Most general powers of attorney would grant you that power, but you should read the document first to make sure that you do have that authority. Acting beyond the scope of the power of attorney can also be actionable. If you are unsure, ask a lawyer to look over the document and to consult with you before you act.

I just realized that I misread your question. I thought you asked if it was UNLAWFUL. You asked if it was LAWFUL. Yes, it is lawful and legal to sign loan documents for them, so long as you disclose your agency, the loan is for them, and your POA grants that authority, as discussed in my original answer. Sorry. I hope that the "no" at the beginning, rather than a "yes" didn't throw you off too much.