diff --git a/src/server/api/routers/board.ts b/src/server/api/routers/board.ts
index a057d84b..d68ff6d6 100644
--- a/src/server/api/routers/board.ts
+++ b/src/server/api/routers/board.ts
@@ -210,7 +210,7 @@ export const boardRouter = createTRPCRouter({
           deletedBy: userId,
         });
 
-        if (!deletedLists?.length) {
+        if (!Array.isArray(deletedLists)) {
           throw new TRPCError({
             message: `Failed to delete lists`,
             code: "INTERNAL_SERVER_ERROR",
@@ -223,7 +223,7 @@ export const boardRouter = createTRPCRouter({
           deletedBy: userId,
         });
 
-        if (!deletedCards?.length) {
+        if (!Array.isArray(deletedCards)) {
           throw new TRPCError({
             message: `Failed to delete cards`,
             code: "INTERNAL_SERVER_ERROR",
diff --git a/src/server/api/routers/list.ts b/src/server/api/routers/list.ts
index 2383e83a..c460fda5 100644
--- a/src/server/api/routers/list.ts
+++ b/src/server/api/routers/list.ts
@@ -53,7 +53,8 @@ export const listRouter = createTRPCRouter({
         name: input.name,
         createdBy: userId,
         boardId: board.id,
-        index: latestListIndex ? latestListIndex + 1 : 0,
+        index:
+          latestListIndex || latestListIndex === 0 ? latestListIndex + 1 : 0,
       });
 
       if (!result)
@@ -161,7 +162,7 @@ export const listRouter = createTRPCRouter({
         deletedBy: userId,
       });
 
-      if (!deletedCards?.length)
+      if (!Array.isArray(deletedCards))
         throw new TRPCError({
           message: `Failed to delete cards`,
           code: "INTERNAL_SERVER_ERROR",
@@ -177,7 +178,7 @@ export const listRouter = createTRPCRouter({
 
       await listRepo.shiftIndex(ctx.db, {
         boardId: list.boardId,
-        listIndex: list.id,
+        listIndex: list.index,
       });
 
       return { success: true };
diff --git a/src/views/board/components/DeleteListConfirmation.tsx b/src/views/board/components/DeleteListConfirmation.tsx
index 17d3237e..2601cf5e 100644
--- a/src/views/board/components/DeleteListConfirmation.tsx
+++ b/src/views/board/components/DeleteListConfirmation.tsx
@@ -1,6 +1,7 @@
 import { api } from "~/utils/api";
 import { useBoard } from "~/providers/board";
 import { useModal } from "~/providers/modal";
+import { usePopup } from "~/providers/popup";
 
 import Button from "~/components/Button";
 
@@ -14,6 +15,7 @@ export function DeleteListConfirmation({
   const utils = api.useUtils();
   const { boardData } = useBoard();
   const { closeModal } = useModal();
+  const { showPopup } = usePopup();
 
   const refetchBoard = async () => {
     if (boardData?.publicId) {
@@ -30,6 +32,14 @@ export function DeleteListConfirmation({
       closeModal();
       return refetchBoard();
     },
+    onError: async () => {
+      closeModal();
+      await refetchBoard();
+      showPopup({
+        header: "Unable to delete list",
+        message: "Please try again later, or contact customer support.",
+      });
+    },
   });
 
   return (
@@ -46,7 +56,10 @@ export function DeleteListConfirmation({
         <Button onClick={() => closeModal()} variant="secondary">
           Cancel
         </Button>
-        <Button onClick={() => deleteList.mutate({ listPublicId })}>
+        <Button
+          isLoading={deleteList.isPending}
+          onClick={() => deleteList.mutate({ listPublicId })}
+        >
           Delete
         </Button>
       </div>
diff --git a/supabase/seed.sql b/supabase/seed.sql
index f41c1da5..676ff13d 100644
--- a/supabase/seed.sql
+++ b/supabase/seed.sql
@@ -1,20 +1,36 @@
 CREATE OR REPLACE FUNCTION reorder_lists(board_id BIGINT, list_id BIGINT, current_index INT, new_index INT)
-RETURNS VOID
-LANGUAGE SQL
-AS $$  
-  UPDATE list
-    SET index =
-      CASE
-        WHEN index = current_index AND id = list_id THEN new_index
-        WHEN current_index < new_index AND index > current_index AND index <= new_index THEN index - 1
-        WHEN current_index > new_index AND index >= new_index AND index < current_index THEN index + 1
-        ELSE index
-      END
-    WHERE "boardId" = board_id;
+RETURNS BOOLEAN
+LANGUAGE PLPGSQL
+AS $$
+BEGIN
+    UPDATE list
+      SET index =
+        CASE
+          WHEN index = current_index AND id = list_id THEN new_index
+          WHEN current_index < new_index AND index > current_index AND index <= new_index THEN index - 1
+          WHEN current_index > new_index AND index >= new_index AND index < current_index THEN index + 1
+          ELSE index
+        END
+      WHERE "boardId" = board_id;
+
+    -- Check for duplicate indices after the update
+    IF EXISTS (
+      SELECT index, COUNT(*)
+      FROM list 
+      WHERE "boardId" = board_id 
+      AND "deletedAt" IS NULL
+      GROUP BY index
+      HAVING COUNT(*) > 1
+    ) THEN
+      RAISE EXCEPTION 'Duplicate indices found after reordering in board %', board_id;
+    END IF;
+
+    RETURN TRUE;
+END;
 $$;
 
 CREATE OR REPLACE FUNCTION reorder_cards(card_id BIGINT, current_list_id BIGINT, new_list_id BIGINT, current_index INT, new_index INT)
-RETURNS VOID
+RETURNS BOOLEAN
 LANGUAGE PLPGSQL
 AS $$
   DECLARE
@@ -45,8 +61,22 @@ AS $$
           SET "listId" = new_list_id, index = new_index
           WHERE id = card_id AND "deletedAt" IS NULL;
       END IF;
+
+      -- Check for duplicate indices in both affected lists
+      IF EXISTS (
+        SELECT index, COUNT(*)
+        FROM card 
+        WHERE "listId" IN (current_list_id, new_list_id)
+        AND "deletedAt" IS NULL
+        GROUP BY "listId", index
+        HAVING COUNT(*) > 1
+      ) THEN
+        RAISE EXCEPTION 'Duplicate indices found after reordering in list % or %', current_list_id, new_list_id;
+      END IF;
+
+      RETURN TRUE;
   END;
-$$
+$$;
 
 CREATE OR REPLACE FUNCTION shift_list_index(board_id BIGINT, list_index INT)
 RETURNS VOID