Discount codes usually are not specific to individual locations. Rental agents sometimes do ask for proof that you work for the company or organization a particular code is associated with so you're always taking a risk if you use one you're not authorized for. There's also a risk that you may run into trouble if you get into an accident and the reservation was booked with a code you do not qualify for since some discount codes include insurance and the claim is then reported to the company who the discount code belongs to. Even if insurance is not automatic, the company or organization may still get notified of any claims made on a rental that uses their code.