# File lib/active_merchant/billing/gateways/authorize_net.rb, line 150
      def credit(money, identification, options = {})
        requires!(options, :card_number)

        post = { :trans_id => identification,
                 :card_num => options[:card_number]
               }
        add_invoice(post, options)

        commit('CREDIT', money, post)
      end