Cardholders in contracting organizations must adhere to which regulations when using the card for contractual payments?

The Federal Acquisition Regulation (FAR) is the primary regulation governing the procurement process for federal agencies, including those under the Department of Defense. When cardholders in contracting organizations use government purchase cards for contractual payments, they must ensure their actions are compliant with FAR requirements. The FAR outlines the policies and procedures for federal procurement, including how to properly conduct transactions, manage contracts, and ensure accountability and transparency in the procurement process. Adhering to these regulations is essential to uphold the integrity and legality of the purchasing process when government resources are used.

While each of the other choices represents important regulations or guidelines relevant to federal spending, they do not specifically cover the procurement processes in as comprehensive a manner as FAR does. GSA requirements focus more on the management and operation of shared services, DoD policies can provide specific directives for military procurement but may not address all aspects covered by FAR, and OMB guidelines generally set broader financial management principles rather than the procurement rules mandated by FAR.