Any company or employee purchase that does not meet a company's purchasing policy. This includes using off-contract methods of procurement and non-authorized purchases. Also called Rogue Purchasing.
Maverick buying, for example, is when employees buy office articles at the local store around the corner instead of from the supplier with whom the company has negotiated a framework agreement and, therefore, specific discounts. Maverick buying makes the agreement with the supplier more expensive because the volume of the framework agreement is decreased or the goods are purchased at too high a price.