If you normally use Purchase Orders to pay for your office supplies, you must set up a revolving credit account with us. Click here to fill out an application. You may also use a major credit card –– MasterCard, American Express, VISA, or Discover –– to pay for your order. Purchase Order numbers can be entered at the Payment Information screen when you place your order, or on the Review Order page. Please note that the Purchase Order number is for your records only. It will be referenced on your packing slip to make your recordkeeping easier.