diff --git a/rfid/rfid.ino b/rfid/rfid.ino
index 757b6aa..3f8536c 100644
--- a/rfid/rfid.ino
+++ b/rfid/rfid.ino
@@ -104,7 +104,13 @@ boolean getID()
   for ( uint8_t i = 0; i < 4; i++) {
   //readCard[i] = mfrc522.uid.uidByte[i];
   // Adds the 4 bytes in a single String variable
-  tagID.concat(String(mfrc522.uid.uidByte[i], HEX));
+  uint8_t value = mfrc522.uid.uidByte[i];
+  // Checks to see if the value is smaller 
+  // than 16 (0x10) and adds the 0 padding needed if needed
+  if (value<0x10) {
+    tagID.concat("0");  
+  }
+  tagID.concat(String(value, HEX));
   }
   //MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
   tagID.toUpperCase();
@@ -112,3 +118,4 @@ boolean getID()
   return true;
   //MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
 }
+