diff --git a/lib/tracking_number/base.rb b/lib/tracking_number/base.rb
index dd22ea2..e22b162 100644
--- a/lib/tracking_number/base.rb
+++ b/lib/tracking_number/base.rb
@@ -35,6 +35,24 @@ def self.scan(body)
       end
     end
 
+    def self.tracking_url(*trackers)
+      if not trackers.all? { |t| t.class == self }
+        raise ArgumentError, "all tracking numbers must be of same class"
+      end
+      url = nil
+      courier = trackers.first.matching_additional["Courier"]
+      if courier
+        url = courier[:tracking_url]
+      else
+        if self.const_defined?(:TRACKING_URL)
+          url = self.const_get(:TRACKING_URL)
+        end
+      end
+      if url
+        url.sub('%s', trackers.map(&:tracking_number).join(','))
+      end
+    end
+
     def serial_number
       return match_group("SerialNumber") unless self.class.const_get("VALIDATION")
 
@@ -170,18 +188,7 @@ def shipper_id
     end
 
     def tracking_url
-      url = nil
-      if matching_additional["Courier"]
-        url = matching_additional["Courier"][:tracking_url]
-      else
-        if self.class.const_defined?(:TRACKING_URL)
-          url = self.class.const_get(:TRACKING_URL)
-        end
-      end
-
-      if url
-        url.sub('%s', self.tracking_number)
-      end
+      self.class.tracking_url self
     end
 
     def matching_additional