diff --git a/public/js/pages/Cpeprovisioning/Cpeprovisioning.js b/public/js/pages/Cpeprovisioning/Cpeprovisioning.js
index 6cf017632..0325a6e6f 100644
--- a/public/js/pages/Cpeprovisioning/Cpeprovisioning.js
+++ b/public/js/pages/Cpeprovisioning/Cpeprovisioning.js
@@ -378,7 +378,8 @@ Vue.component('Cpeprovisioning', {
 
         handleMacInput(item, val) {
             if (val !== undefined) {
-                item.cpe_data.mac = val;
+                // Fix encoding issue: replace ß (scharfes s) with - before processing
+                item.cpe_data.mac = val.replace(/ß/g, '-');
             }
 
             const itemKey = item.orderproduct_id;
@@ -414,11 +415,17 @@ Vue.component('Cpeprovisioning', {
         },
         
         processMacAddress(item) {
-            const inputValue = item.cpe_data.mac;
+            let inputValue = item.cpe_data.mac;
             const routerType = item.cpe_data.routertype;
 
             if (!inputValue) return;
 
+            // Fix encoding issue: replace ß (scharfes s) with - before processing
+            if (inputValue.includes('ß')) {
+                inputValue = inputValue.replace(/ß/g, '-');
+                this.$set(item.cpe_data, 'mac', inputValue); // Update field with corrected value
+            }
+
             // Only process QR codes for FritzBox 4050 and 7690
             if (routerType === 'FritzBox 4050' || routerType === 'FritzBox 7690') {
                 const parsedMac = this.parseMacFromQrCode(inputValue);