diff --git a/src/utils/formatAmount.ts b/src/utils/formatAmount.ts
index f4c8ddc1..dcc845a4 100644
--- a/src/utils/formatAmount.ts
+++ b/src/utils/formatAmount.ts
@@ -6,6 +6,11 @@
  */
 
 export function formatAmount(amount: number): string {
+  // NaN, undefined, null 처리
+  if (amount == null || isNaN(amount)) {
+    return "0원";
+  }
+
   if (amount < 10000) {
     return `${amount.toLocaleString("ko-KR")}원`;
   } else {
@@ -18,6 +23,10 @@ export function formatAmount(amount: number): string {
  * 금액을 원 단위로 포맷 (항상 "원" 단위)
  */
 export function formatAmountWon(amount: number): string {
+  // NaN, undefined, null 처리
+  if (amount == null || isNaN(amount)) {
+    return "0원";
+  }
   return `${amount.toLocaleString("ko-KR")}원`;
 }