diff --git a/couriers/ups.json b/couriers/ups.json
index 2804214..a071330 100644
--- a/couriers/ups.json
+++ b/couriers/ups.json
@@ -6,7 +6,7 @@
       "name": "UPS",
       "id": "ups",
       "regex": [
-        "\\s*1\\s*Z\\s*(?<SerialNumber>",
+        "\\s*1\\s*[Zz]\\s*(?<SerialNumber>",
         "(?<ShipperId>(?:[A-Z0-9]\\s*){6,6})",
         "(?<ServiceType>(?:[A-Z0-9]\\s*){2,2})",
         "(?<PackageId>(?:[A-Z0-9]\\s*){7,7}))",
@@ -127,7 +127,8 @@
           "1Z410E7W0392751591",
           "1Z8V92A70367203024",
           " 1 Z 8 V 9 2 A 7 0 3 6 7 2 0 3 0 2 4 ",
-          "1ZXX3150YW44070023"
+          "1ZXX3150YW44070023",
+          "1zXX3150YW44070023"
         ],
         "invalid": [
           "2Z5R89390357567127",