diff --git a/app/modules/expense/db.py b/app/modules/expense/db.py
index 39af638..5453a02 100644
--- a/app/modules/expense/db.py
+++ b/app/modules/expense/db.py
@@ -398,7 +398,7 @@ class ExpenseDBStore:
                 """
                 SELECT a.id, a.item_id, a.owner, a.kind, a.filename,
                        a.stored_path, a.content_type, a.uploaded_at,
-                       i.spent_at
+                       i.spent_at, i.category, i.method, i.amount, i.merchant
                   FROM expense_attachments a
                   JOIN expense_items i ON i.id = a.item_id
                  WHERE i.status = ANY(%s)
diff --git a/app/modules/expense/router.py b/app/modules/expense/router.py
index 1dcc350..fd70b6b 100644
--- a/app/modules/expense/router.py
+++ b/app/modules/expense/router.py
@@ -105,15 +105,47 @@ def _display_name(email: str, names: dict[str, str]) -> str:
     return names.get(email) or (email.split("@")[0] if email else "")
 
 
-def _att_download_name(uploaded_at: Any, name: str, original: str) -> str:
-    """첨부 다운로드 파일명: `yy년 mm월 dd일(요일)_이름{ext}`. 날짜=업로드일(KST)."""
-    if isinstance(uploaded_at, datetime):
-        d = uploaded_at.astimezone(KST)
-    else:
-        d = now_kst()
-    wd = _WEEKDAYS_KR[d.weekday()]
-    base = f"{d.strftime('%y')}년 {d.strftime('%m')}월 {d.strftime('%d')}일({wd})_{name}"
-    ext = os.path.splitext(original or "")[1].lower()
+def _safe_part(value: Any) -> str:
+    """파일명 구성요소 정리 — 경로/금지문자 제거, 공백 압축."""
+    s = str(value or "").strip()
+    s = re.sub(r"[\\/:*?\"<>|\r\n\t]", " ", s)
+    s = re.sub(r"\s+", " ", s).strip()
+    return s
+
+
+def _fmt_date_kr(value: Any) -> str:
+    """날짜 → `yy년 mm월 dd일(요일)`. date/datetime/문자열(YYYY-MM-DD) 허용."""
+    d: Any = value
+    if isinstance(value, str):
+        try:
+            d = datetime.strptime(value[:10], "%Y-%m-%d").date()
+        except ValueError:
+            return _safe_part(value)
+    if isinstance(d, datetime):
+        d = d.astimezone(KST)
+    if hasattr(d, "weekday"):
+        wd = _WEEKDAYS_KR[d.weekday()]
+        return f"{d.strftime('%y')}년 {d.strftime('%m')}월 {d.strftime('%d')}일({wd})"
+    return _safe_part(value)
+
+
+def _att_download_name(att: dict[str, Any], name: str) -> str:
+    """첨부 다운로드 파일명: `날짜_이름_분류_결제수단_금액_가맹점{ext}`.
+
+    날짜=사용일(spent_at). 금액=쉼표 표기. 빈 가맹점은 생략.
+    """
+    parts = [
+        _fmt_date_kr(att.get("spent_at")),
+        _safe_part(name),
+        _safe_part(att.get("category")),
+        _safe_part(att.get("method")),
+        f"{int(att.get('amount', 0) or 0):,}원",
+    ]
+    merchant = _safe_part(att.get("merchant"))
+    if merchant:
+        parts.append(merchant)
+    base = "_".join(p for p in parts if p)
+    ext = os.path.splitext(att.get("filename") or "")[1].lower()
     return f"{base}{ext}"
 
 
@@ -559,7 +591,7 @@ async def approved_attachments_zip(
                 missing += 1
                 continue
             nm = _display_name(a.get("owner", ""), names)
-            fname = _att_download_name(a.get("uploaded_at"), nm, a.get("filename", ""))
+            fname = _att_download_name(a, nm)
             # 동일명 충돌 → 접미사
             if fname in used:
                 used[fname] += 1
diff --git a/app/modules/expense/templates/expense/index.html b/app/modules/expense/templates/expense/index.html
index 64309bd..962f90d 100644
--- a/app/modules/expense/templates/expense/index.html
+++ b/app/modules/expense/templates/expense/index.html
@@ -69,7 +69,7 @@
         <input type="number" name="amount" min="0" step="1" required placeholder="원" />
       </label>
       <label class="erp-field erp-field-wide"><span>가맹점/사용처</span>
-        <input type="text" name="merchant" placeholder="예) 스타벅스 강남점" />
+        <input type="text" name="merchant" placeholder="예) 스타벅스 강남점" required />
       </label>
       <label class="erp-field erp-field-wide"><span>메모</span>
         <input type="text" name="memo" placeholder="비고" />
@@ -258,8 +258,37 @@
   }
   resetBtn.addEventListener("click", () => setEditing("", null));
 
+  // 필수 입력 검증 — 누락 시 경고창
+  function validateRequired() {
+    const required = [
+      ["spent_at", "사용일"],
+      ["category", "분류"],
+      ["method", "결제수단"],
+      ["amount", "금액"],
+      ["merchant", "가맹점/사용처"],
+    ];
+    const missing = [];
+    for (const [field, label] of required) {
+      const val = (form[field].value || "").trim();
+      if (!val) missing.push([form[field], label]);
+    }
+    // 금액은 0 이하도 미입력 취급
+    if (!missing.some(([f]) => f === form.amount)) {
+      if (!(parseInt(form.amount.value, 10) > 0)) {
+        missing.push([form.amount, "금액(1원 이상)"]);
+      }
+    }
+    if (missing.length) {
+      alert("다음 항목을 입력하세요:\n- " + missing.map(([, l]) => l).join("\n- "));
+      missing[0][0].focus();
+      return false;
+    }
+    return true;
+  }
+
   form.addEventListener("submit", async (e) => {
     e.preventDefault();
+    if (!validateRequired()) return;
     const id = form.id.value.trim();
     const payload = {
       spent_at: form.spent_at.value,