diff --git a/d2-tracker/dhis2.angular.services.js b/d2-tracker/dhis2.angular.services.js
index 47f75187e..2c9be7a9f 100644
--- a/d2-tracker/dhis2.angular.services.js
+++ b/d2-tracker/dhis2.angular.services.js
@@ -447,22 +447,48 @@ var d2Services = angular.module('d2Services', ['ngResource'])
     return {
         getCode: function(options, key){
             if(options){
+                // for comparison with the option values, which are always represented as strings
+                const keyString = String(key);
+
+                // is key a name?
                 for(var i=0; i<options.length; i++){
-                    if( key === options[i].displayName){
+                    if( keyString === options[i].displayName){
                         return options[i].code;
                     }
                 }
+                // is key a code?
+                for(var i=0; i<options.length; i++){
+                    if( keyString === options[i].code){
+                        return key;
+                    }
+                }
+                // not a part of the option set
+                return null;
             }
+
             return key;
         },
         getName: function(options, key){
             if(options){
+                // for comparison with the option values, which are always represented as strings
+                const keyString = String(key);
+
+                // is key a code?
                 for(var i=0; i<options.length; i++){
-                    if( key === options[i].code){
+                    if( keyString === options[i].code){
                         return options[i].displayName;
                     }
                 }
+                // is key a name?
+                for(var i=0; i<options.length; i++){
+                    if( keyString === options[i].displayName){
+                        return key;
+                    }
+                }
+                // not a part of the option set
+                return null;
             }
+
             return key;
         }
     };