implemented pr (worth fixing) feedback

update commit

frontend/src/components/AddNotificationModal.tsx

@@ -36,6 +36,7 @@ export function AddNotificationModal({ provider, onClose }: AddNotificationModal
   const [onPrintFailed, setOnPrintFailed] = useState(provider?.on_print_failed ?? true);
   const [onPrintStopped, setOnPrintStopped] = useState(provider?.on_print_stopped ?? true);
   const [onPrintProgress, setOnPrintProgress] = useState(provider?.on_print_progress ?? false);
+  const [onBillingChargeFailed, setOnBillingChargeFailed] = useState(provider?.on_billing_charge_failed ?? true);
   const [onPrinterOffline, setOnPrinterOffline] = useState(provider?.on_printer_offline ?? false);
   const [onPrinterError, setOnPrinterError] = useState(provider?.on_printer_error ?? false);
   const [onAiFailureDetection, setOnAiFailureDetection] = useState(provider?.on_ai_failure_detection ?? false);
@@ -192,6 +193,7 @@ export function AddNotificationModal({ provider, onClose }: AddNotificationModal
       on_print_failed: onPrintFailed,
       on_print_stopped: onPrintStopped,
       on_print_progress: onPrintProgress,
+      on_billing_charge_failed: onBillingChargeFailed,
       on_printer_offline: onPrinterOffline,
       on_printer_error: onPrinterError,
       on_ai_failure_detection: onAiFailureDetection,
@@ -605,6 +607,13 @@ export function AddNotificationModal({ provider, onClose }: AddNotificationModal
                   </div>
                   <Toggle checked={onPrintProgress} onChange={setOnPrintProgress} />
                 </div>
+                <div className="flex items-center justify-between col-span-2">
+                  <div>
+                    <span className="text-sm text-white">{t('notifications.billingChargeFailedLabel')}</span>
+                    <span className="text-xs text-bambu-gray ml-1">{t('notifications.billingChargeFailedDescription')}</span>
+                  </div>
+                  <Toggle checked={onBillingChargeFailed} onChange={setOnBillingChargeFailed} />
+                </div>
                 <div className="flex items-center justify-between col-span-2">
                   <div>
                     <span className="text-sm text-white">{t('notifications.plateClearRequired')}</span>
@@ -692,6 +701,7 @@ export function AddNotificationModal({ provider, onClose }: AddNotificationModal
               if (onPrintFailed) enabledEvents.push({ key: 'on_print_failed', label: t('notifications.failed') });
               if (onPrintStopped) enabledEvents.push({ key: 'on_print_stopped', label: t('notifications.stopped') });
               if (onPrintProgress) enabledEvents.push({ key: 'on_print_progress', label: t('notifications.progress') });
+              if (onBillingChargeFailed) enabledEvents.push({ key: 'on_billing_charge_failed', label: t('notifications.billingChargeFailedLabel') });
               if (onPlateClearRequired) enabledEvents.push({ key: 'on_plate_clear_required', label: t('notifications.plateClearRequired') });
               if (onBedCooled) enabledEvents.push({ key: 'on_bed_cooled', label: t('notifications.bedCooled') });
               if (onFirstLayerComplete) enabledEvents.push({ key: 'on_first_layer_complete', label: t('notifications.firstLayerCompleteLabel') });

frontend/src/components/NotificationProviderCard.tsx

@@ -132,6 +132,9 @@ export function NotificationProviderCard({ provider, onEdit }: NotificationProvi
             {provider.on_print_stopped && (
               <span className="px-2 py-0.5 bg-orange-100 dark:bg-orange-500/20 text-orange-700 dark:text-orange-400 text-xs rounded">{t('notifications.stopped')}</span>
             )}
+            {provider.on_billing_charge_failed && (
+              <span className="px-2 py-0.5 bg-red-100 dark:bg-red-600/20 text-red-700 dark:text-red-300 text-xs rounded">{t('notifications.billingChargeFailedLabel')}</span>
+            )}
             {provider.on_print_progress && (
               <span className="px-2 py-0.5 bg-yellow-100 dark:bg-yellow-500/20 text-yellow-700 dark:text-yellow-400 text-xs rounded">{t('notifications.progress')}</span>
             )}
@@ -354,6 +357,17 @@ export function NotificationProviderCard({ provider, onEdit }: NotificationProvi
                   />
                 </div>
 
+                <div className="flex items-center justify-between">
+                  <div>
+                    <p className="text-sm text-white">{t('notifications.billingChargeFailedLabel')}</p>
+                    <p className="text-xs text-bambu-gray">{t('notifications.billingChargeFailedDescription')}</p>
+                  </div>
+                  <Toggle
+                    checked={provider.on_billing_charge_failed ?? true}
+                    onChange={(checked) => updateMutation.mutate({ on_billing_charge_failed: checked })}
+                  />
+                </div>
+
                 <div className="flex items-center justify-between">
                   <div>
                     <p className="text-sm text-white">{t('notifications.progressMilestones')}</p>

frontend/src/components/PrintModal/CostCenterSelect.tsx

@@ -15,6 +15,7 @@ export function CostCenterSelect({
   const { t } = useTranslation();
 
   if (costCenters.length === 0) return null;
+  const selectedCostCenter = costCenters.find((center) => center.id === selectedCostCenterId);
 
   return (
     <div className="space-y-1">
@@ -33,6 +34,11 @@ export function CostCenterSelect({
           </option>
         ))}
       </select>
+      {selectedCostCenter?.budget_mode === 'none' && (
+        <p className="text-xs text-bambu-gray">
+          {t('printModal.unlimitedNoBudget', 'Unlimited – no budget limit is set.')}
+        </p>
+      )}
     </div>
   );
 }

frontend/src/components/PrintModal/index.tsx

@@ -315,7 +315,7 @@ export function PrintModal({
     queryFn: api.getPrinters,
   });
 
-  const { data: myCostCenters } = useQuery({
+  const { data: myCostCenters, isLoading: loadingCostCenters } = useQuery({
     queryKey: ['finance', 'cost-centers', 'mine'],
     queryFn: api.getMyCostCenters,
     enabled: !!user && billingEnabled,
@@ -824,6 +824,11 @@ export function PrintModal({
   const handleSubmit = async (e?: React.FormEvent, options?: { skipFilamentCheck?: boolean }) => {
     e?.preventDefault();
 
+    if (billingEnabled && selectedCostCenter == null) {
+      showToast(t('printModal.noPrintableCostCenters'), 'error');
+      return;
+    }
+
     if (
       !options?.skipFilamentCheck &&
       !settings?.disable_filament_warnings &&
@@ -1277,6 +1282,11 @@ export function PrintModal({
   const canSubmit = useMemo(() => {
     if (isPending) return false;
 
+    // Billing requires a server-authorized cost center. Wait for the query and
+    // keep submission disabled when the user has no printable center, rather
+    // than letting the API fail with an unexplained 400.
+    if (billingEnabled && (loadingCostCenters || selectedCostCenter == null)) return false;
+
     // Need valid printer/model selection
     if (assignmentMode === 'printer' && selectedPrinters.length === 0) return false;
     // Both are about the single-model case. A cross-model job has no one target
@@ -1313,6 +1323,9 @@ export function PrintModal({
     perPlateReqsFailed,
     printerStatusLoading,
     isCrossModel,
+    billingEnabled,
+    loadingCostCenters,
+    selectedCostCenter,
   ]);
 
   // Quantity only applies for single-printer or model-based assignment (not multi-printer)
@@ -1714,6 +1727,15 @@ export function PrintModal({
                 onChange={setSelectedCostCenterId}
               />
             )}
+            {billingEnabled && !loadingCostCenters && printableCostCenters.length === 0 && (
+              <div
+                role="alert"
+                className="p-3 bg-yellow-100 dark:bg-yellow-500/20 border border-yellow-500/50 rounded-lg text-sm text-yellow-800 dark:text-yellow-300 flex items-start gap-2"
+              >
+                <AlertTriangle className="w-4 h-4 mt-0.5 shrink-0" />
+                {t('printModal.noPrintableCostCenters')}
+              </div>
+            )}
 
             {/* Quantity — create multiple copies (batch). Hidden for multi-printer
                 selection, and for multi-plate files where the per-plate steppers