diff --git a/apps/librarian/lib/modules/loans/checkout/stepper/items/connected_thing_search_field.dart b/apps/librarian/lib/modules/loans/checkout/stepper/items/connected_thing_search_field.dart
index d8ce017..5f2e230 100644
--- a/apps/librarian/lib/modules/loans/checkout/stepper/items/connected_thing_search_field.dart
+++ b/apps/librarian/lib/modules/loans/checkout/stepper/items/connected_thing_search_field.dart
@@ -26,88 +26,72 @@ class ConnectedThingSearchField extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return TextField(
-      controller: _textController,
-      onSubmitted: (_) => _submit(),
-      decoration: InputDecoration(
-        hintText: 'Enter Item Number',
-        prefixIcon: const Icon(Icons.numbers),
-        suffixIcon: IconButton(
-          tooltip: 'Add Item',
-          onPressed: () => _submit(),
-          icon: const Icon(Icons.add_rounded),
-        ),
-      ),
-      inputFormatters: [
-        FilteringTextInputFormatter.digitsOnly,
-      ],
-    );
+    return ListenableBuilder(
+        listenable: controller,
+        builder: (context, child) {
+          return TextField(
+            controller: _textController,
+            onSubmitted: (_) => _submit(),
+            decoration: InputDecoration(
+              errorText: controller.errorText,
+              hintText: 'Enter Item Number',
+              prefixIcon: const Icon(Icons.numbers),
+              suffixIcon: IconButton(
+                tooltip: 'Add Item',
+                onPressed: () => _submit(),
+                icon: const Icon(Icons.add_rounded),
+              ),
+            ),
+            inputFormatters: [
+              FilteringTextInputFormatter.digitsOnly,
+            ],
+          );
+        });
   }
 }
 
-class ThingSearchController {
+class ThingSearchController extends ChangeNotifier {
   final BuildContext context;
+  final List<ItemModel> items;
   final InventoryRepository repository;
   final void Function(ItemModel) onMatchFound;
 
   bool isLoading = false;
 
+  String? errorText;
+
   ThingSearchController({
     required this.context,
+    required this.items,
     required this.repository,
     required this.onMatchFound,
   });
 
   Future<void> search(String value) async {
+    final itemNumber = int.parse(value);
+
+    if (items.any((t) => t.number == itemNumber)) {
+      errorText = '#$value is already added to this loan.';
+      notifyListeners();
+      return;
+    }
+
     isLoading = true;
-    final match = await repository.getItem(number: int.parse(value));
+    final match = await repository.getItem(number: itemNumber);
     isLoading = false;
 
-    if (match != null) {
-      if (!match.available) {
-        _showThingCheckedOutDialog(match);
-      } else {
-        onMatchFound(match);
-      }
-    } else {
-      _showUnknownThingDialog(value);
+    if (match == null) {
+      errorText = '#$value could not be found.';
+      notifyListeners();
+      return;
     }
-  }
 
-  void _showThingCheckedOutDialog(ItemModel thing) {
-    showDialog(
-      context: context,
-      builder: (context) {
-        return AlertDialog(
-          title: const Text("Item Unavailable"),
-          content: Text(
-              "Item #${thing.number} is checked out or not available for lending."),
-          actions: [
-            TextButton(
-              child: const Text("OK"),
-              onPressed: () => Navigator.pop(context),
-            )
-          ],
-        );
-      },
-    );
-  }
+    if (!match.available) {
+      errorText = '#$value is unavailable.';
+      notifyListeners();
+      return;
+    }
 
-  void _showUnknownThingDialog(String searchValue) {
-    showDialog(
-      context: context,
-      builder: (context) {
-        return AlertDialog(
-          title: Text("Item #$searchValue does not exist."),
-          content: const Text("Try another number."),
-          actions: [
-            TextButton(
-              child: const Text("OK"),
-              onPressed: () => Navigator.pop(context),
-            )
-          ],
-        );
-      },
-    );
+    onMatchFound(match);
   }
 }
diff --git a/apps/librarian/lib/modules/loans/checkout/stepper/items/existing_item_dialog.dart b/apps/librarian/lib/modules/loans/checkout/stepper/items/existing_item_dialog.dart
deleted file mode 100644
index e1d99ad..0000000
--- a/apps/librarian/lib/modules/loans/checkout/stepper/items/existing_item_dialog.dart
+++ /dev/null
@@ -1,23 +0,0 @@
-import 'package:flutter/material.dart';
-
-class ExistingItemDialog extends StatelessWidget {
-  const ExistingItemDialog({super.key, required this.number});
-
-  final int number;
-
-  @override
-  Widget build(BuildContext context) {
-    return AlertDialog(
-      title: Text('Item #$number Already Added'),
-      content: const Text("The item can't be added again."),
-      actions: [
-        FilledButton(
-          onPressed: () {
-            Navigator.of(context).pop();
-          },
-          child: const Text('OK'),
-        ),
-      ],
-    );
-  }
-}
diff --git a/apps/librarian/lib/modules/loans/checkout/stepper/items/items_step.dart b/apps/librarian/lib/modules/loans/checkout/stepper/items/items_step.dart
index 8cd06ae..9715eb4 100644
--- a/apps/librarian/lib/modules/loans/checkout/stepper/items/items_step.dart
+++ b/apps/librarian/lib/modules/loans/checkout/stepper/items/items_step.dart
@@ -5,7 +5,6 @@ import 'package:librarian_app/modules/things/providers/things_repository_provide
 import 'package:librarian_app/widgets/item_card.dart';
 
 import 'connected_thing_search_field.dart';
-import 'existing_item_dialog.dart';
 import 'eye_protection_dialog.dart';
 import 'suggested_things_dialog.dart';
 
@@ -27,20 +26,11 @@ Step buildItemsStep({
         ConnectedThingSearchField(
           controller: ThingSearchController(
             context: context,
-            onMatchFound: (thing) {
-              if (items.any((t) => t.id == thing.id)) {
-                showDialog(
-                  context: context,
-                  builder: (context) {
-                    return ExistingItemDialog(number: thing.number);
-                  },
-                );
-                return;
-              }
-
-              onAddItem(thing);
+            items: items,
+            onMatchFound: (item) {
+              onAddItem(item);
 
-              if (thing.eyeProtection && !didPromptForEyeProtection) {
+              if (item.eyeProtection && !didPromptForEyeProtection) {
                 showDialog(
                   context: context,
                   builder: (_) => const EyeProtectionDialog(),
@@ -48,12 +38,12 @@ Step buildItemsStep({
                 onPromptForEyeProtection();
               }
 
-              if (thing.linkedThingIds.isNotEmpty) {
+              if (item.linkedThingIds.isNotEmpty) {
                 showDialog(
                   context: context,
                   builder: (_) => SuggestedThingsDialog(
-                    thingName: thing.name,
-                    thingIds: thing.linkedThingIds,
+                    thingName: item.name,
+                    thingIds: item.linkedThingIds,
                   ),
                 );
               }