Can You Accept Volunteer Labor? - HR Daily Advisor
Volunteering can be a great way to get some experience when you're first getting started in a field. However, you should volunteer for a nonprofit. You can't volunteer for a for-profit company.
Asking a company if you can do free work for them tells that company that you believe they will violate federal law to take advantage of you. You're not doing them a favor. You're asking them to do an enormous amount of work by having an attorney help them create an unpaid internship program just for you.
Most for-profit organizations cannot accept volunteer, unpaid labor without running afoul of the FLSA.
Even interns must be paid in most circumstances—if they’re performing tasks that benefit the employer (as opposed to just learning and observing), they’re completing work that is entitled to pay. This is true even if the intern <em>offers</em> his or her services for free just to get started with the organization.