diff --git a/app/hooks/cost-surface/index.ts b/app/hooks/cost-surface/index.ts
index 4bd03899dd..e69927f0ed 100644
--- a/app/hooks/cost-surface/index.ts
+++ b/app/hooks/cost-surface/index.ts
@@ -19,16 +19,19 @@ export function useProjectCostSurfaces<T = CostSurface[]>(
     {
       id: 'gfehrtf22534geyg',
       name: 'Cost Surface Rwanda A',
+      isCustom: true,
       scenarioUsageCount: 3,
     },
     {
       id: 'rfjghhrtersdtbkjshfw',
       name: 'Cost Surface Rwanda B',
+      isCustom: true,
       scenarioUsageCount: 0,
     },
     {
       id: '23275455HGVVCMSJHDFk',
       name: 'Cost Surface Rwanda C',
+      isCustom: true,
       scenarioUsageCount: 0,
     },
   ];
diff --git a/app/layout/project/sidebar/project/inventory-panel/components/inventory-table/types.ts b/app/layout/project/sidebar/project/inventory-panel/components/inventory-table/types.ts
index 87b464baed..55942fbe87 100644
--- a/app/layout/project/sidebar/project/inventory-panel/components/inventory-table/types.ts
+++ b/app/layout/project/sidebar/project/inventory-panel/components/inventory-table/types.ts
@@ -6,7 +6,7 @@ export type DataItem = {
   scenarios: number;
   tag?: string;
   isVisibleOnMap: boolean;
-  isCustom: boolean;
+  isCustom?: boolean;
 };
 
 export type InventoryTable = {
diff --git a/app/layout/project/sidebar/project/inventory-panel/cost-surfaces/index.tsx b/app/layout/project/sidebar/project/inventory-panel/cost-surfaces/index.tsx
index 616cdb7ad5..003b2d1fd1 100644
--- a/app/layout/project/sidebar/project/inventory-panel/cost-surfaces/index.tsx
+++ b/app/layout/project/sidebar/project/inventory-panel/cost-surfaces/index.tsx
@@ -45,6 +45,7 @@ const InventoryPanelCostSurface = ({ noData: noDataMessage }: { noData: string }
         data?.map((cs) => ({
           id: cs.id,
           name: cs.name,
+          isCustom: cs.isCustom,
           scenarioUsageCount: cs.scenarioUsageCount,
         })),
       keepPreviousData: true,
@@ -106,11 +107,12 @@ const InventoryPanelCostSurface = ({ noData: noDataMessage }: { noData: string }
 
   const displayBulkActions = selectedCostSurfaceIds.length > 0;
 
-  const data: DataItem[] = allProjectCostSurfacesQuery.data?.map((wdpa) => ({
-    ...wdpa,
-    name: wdpa.name,
-    scenarios: wdpa.scenarioUsageCount,
-    isVisibleOnMap: visibleCostSurfaces?.includes(wdpa.id),
+  const data: DataItem[] = allProjectCostSurfacesQuery.data?.map((cs) => ({
+    ...cs,
+    name: cs.name,
+    scenarios: cs.scenarioUsageCount,
+    isCustom: cs.isCustom,
+    isVisibleOnMap: visibleCostSurfaces?.includes(cs.id),
   }));
 
   return (
diff --git a/app/types/api/cost-surface.ts b/app/types/api/cost-surface.ts
index 5fe2235785..7390ea12ba 100644
--- a/app/types/api/cost-surface.ts
+++ b/app/types/api/cost-surface.ts
@@ -1,5 +1,6 @@
 export interface CostSurface {
   id: string;
   name: string;
+  isCustom: boolean;
   scenarioUsageCount: number;
 }