diff --git a/frontend/src/components/contacts/FilterPanel.tsx b/frontend/src/components/contacts/FilterPanel.tsx
index 329d2cf..59c256c 100644
--- a/frontend/src/components/contacts/FilterPanel.tsx
+++ b/frontend/src/components/contacts/FilterPanel.tsx
@@ -255,7 +255,7 @@ export function FilterPanel({ filters, onFiltersChange, contactType, savedFilter
   // Merge custom field definitions into FIELD_DEFS
   const allFieldDefs = useMemo(() => {
     const baseFields = FIELD_DEFS.filter((f) => !f.key.startsWith('custom.'));
-    if (!customFieldDefs || customFieldDefs.items.length === 0) return baseFields;
+    if (!customFieldDefs || !customFieldDefs.items || customFieldDefs.items.length === 0) return baseFields;
     const customFields: FilterFieldDef[] = customFieldDefs.items
       .filter((def) => def.is_active)
       .map((def) => {
diff --git a/frontend/src/components/contacts/GroupPanel.tsx b/frontend/src/components/contacts/GroupPanel.tsx
index 527907f..cbc697f 100644
--- a/frontend/src/components/contacts/GroupPanel.tsx
+++ b/frontend/src/components/contacts/GroupPanel.tsx
@@ -182,7 +182,7 @@ export function GroupPanel({ groupState, onGroupChange, contactType }: GroupPane
   // Merge custom field definitions into GROUP_FIELDS
   const allGroupFields = useMemo(() => {
     const baseFields = GROUP_FIELDS.filter((f) => !f.key.startsWith('custom.'));
-    if (!customFieldDefs || customFieldDefs.items.length === 0) return baseFields;
+    if (!customFieldDefs || !customFieldDefs.items || customFieldDefs.items.length === 0) return baseFields;
     const customFields: GroupFieldDef[] = customFieldDefs.items
       .filter((def) => def.is_active)
       .map((def) => {
diff --git a/frontend/src/components/contacts/SortPanel.tsx b/frontend/src/components/contacts/SortPanel.tsx
index 10474e0..42af8ad 100644
--- a/frontend/src/components/contacts/SortPanel.tsx
+++ b/frontend/src/components/contacts/SortPanel.tsx
@@ -174,7 +174,7 @@ export function SortPanel({ sortState, onSortChange, contactType }: SortPanelPro
   // Merge custom field definitions into SORT_FIELDS
   const allSortFields = useMemo(() => {
     const baseFields = SORT_FIELDS.filter((f) => !f.key.startsWith('custom.'));
-    if (!customFieldDefs || customFieldDefs.items.length === 0) return baseFields;
+    if (!customFieldDefs || !customFieldDefs.items || customFieldDefs.items.length === 0) return baseFields;
     const customFields: SortFieldDef[] = customFieldDefs.items
       .filter((def) => def.is_active)
       .map((def) => {