diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index 424b6a9d..4d6b255a 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -105,7 +105,7 @@
   },
 
   "customPrompts_form_label_ID_rules": {
-    "message": "Must be unique and without spaces",
+    "message": "Must be unique, lowercase and without spaces",
     "description": ""
   },
 
diff --git a/customprompts/mzta-custom-prompts.css b/customprompts/mzta-custom-prompts.css
index ccf94c52..958d4f5c 100644
--- a/customprompts/mzta-custom-prompts.css
+++ b/customprompts/mzta-custom-prompts.css
@@ -137,4 +137,8 @@ table.prompts_list td.properties{
 .small_label{
     font-size: small;
     font-style: italic;
+}
+
+#txtIdNew, .id_output{
+    text-transform: lowercase;
 }
\ No newline at end of file
diff --git a/customprompts/mzta-custom-prompts.js b/customprompts/mzta-custom-prompts.js
index 3348e202..8c45c13d 100644
--- a/customprompts/mzta-custom-prompts.js
+++ b/customprompts/mzta-custom-prompts.js
@@ -247,7 +247,7 @@ document.addEventListener('DOMContentLoaded', async () => {
         tr.querySelector('.btnEditItem').style.display = 'inline';   // Edit btn
         tr.querySelector('.btnDeleteItem').style.display = 'inline';   // Delete btn
         // Update item data
-        tr.querySelector('.id_show').innerText = tr.querySelector('.id_output').value;
+        tr.querySelector('.id_show').innerText = String(tr.querySelector('.id_output').value).toLocaleLowerCase();
         tr.querySelector('.name_show').innerText = tr.querySelector('.name_output').value;
         tr.querySelector('.text_show').innerText = tr.querySelector('.text_output').value;
         tr.querySelector('.type').innerText = tr.querySelector('.type_output').value;
@@ -326,7 +326,7 @@ document.addEventListener('DOMContentLoaded', async () => {
             return;
         }
         let newItem = promptsList.add({
-            id: txtIdNew.value.trim(),
+            id: String(txtIdNew.value.trim()).toLocaleLowerCase(),
             name: txtNameNew.value.trim(),
             text: txtTextNew.value.trim(),
             type: selectTypeNew.value,