def build_billing_address(soap, options)
        if options[:billing_address]
          options[:billing_address][:first_name], options[:billing_address][:last_name] = split_names(options[:billing_address][:name]) if options[:billing_address][:name]
          soap.BillingAddress 'xsi:type' => 'ns1:Address' do
            ADDRESS_OPTIONS.each do |k, v|