diff --git a/adminfront/src/features/users/UserDetailPage.tsx b/adminfront/src/features/users/UserDetailPage.tsx
index 0f057712..6db94a92 100644
--- a/adminfront/src/features/users/UserDetailPage.tsx
+++ b/adminfront/src/features/users/UserDetailPage.tsx
@@ -148,7 +148,8 @@ function UserDetailPage() {
   const queryClient = useQueryClient();
   const [error, setError] = React.useState<string | null>(null);
   const [successMsg, setSuccessMsg] = React.useState<string | null>(null);
-  const [showPassword, setShowPassword] = React.useState(false);
+  const [isPasswordResetOpen, setIsPasswordResetOpen] = React.useState(false);
+  const [generatedPassword, setGeneratedPassword] = React.useState<string | null>(null);
 
   const { data: profile } = useQuery({
     queryKey: ["me"],
@@ -189,7 +190,6 @@ function UserDetailPage() {
       department: "",
       position: "",
       jobTitle: "",
-      password: "",
       metadata: {},
     },
   });
@@ -197,22 +197,38 @@ function UserDetailPage() {
   const isAdmin =
     profile?.role === "super_admin" || profile?.role === "tenant_admin";
 
+  const resetPasswordMutation = useMutation({
+    mutationFn: (newPass: string) => updateUser(userId, { password: newPass }),
+    onSuccess: (_, newPass) => {
+      setGeneratedPassword(newPass);
+      toast.success(
+        t(
+          "msg.admin.users.detail.password_generated",
+          "사용자 비밀번호가 성공적으로 재설정되었습니다.",
+        ),
+      );
+    },
+    onError: (err: AxiosError<{ error?: string }>) => {
+      toast.error(
+        err.response?.data?.error ||
+          t("msg.admin.users.detail.update_error", "수정에 실패했습니다."),
+      );
+    },
+  });
+
   const handleGeneratePassword = () => {
+    setIsPasswordResetOpen(true);
+    setGeneratedPassword(null);
+  };
+
+  const confirmGeneratePassword = () => {
     const newPass = generateSecurePassword();
-    setValue("password", newPass);
-    setShowPassword(true);
-    toast.success(
-      t(
-        "msg.admin.users.detail.password_generated",
-        "안전한 비밀번호가 생성되었습니다.",
-      ),
-    );
+    resetPasswordMutation.mutate(newPass);
   };
 
   const handleCopyPassword = () => {
-    const pass = watch("password");
-    if (pass) {
-      navigator.clipboard.writeText(pass);
+    if (generatedPassword) {
+      navigator.clipboard.writeText(generatedPassword);
       toast.success(
         t("msg.common.copied_to_clipboard", "클립보드에 복사되었습니다."),
       );
@@ -670,14 +686,34 @@ function UserDetailPage() {
                 </Button>
               </div>
 
-              {showPassword && (
+              {isPasswordResetOpen && !generatedPassword && (
+                <div className="p-4 border rounded-lg bg-destructive/5 space-y-4">
+                  <p className="text-sm">
+                    {t(
+                      "msg.admin.users.detail.reset_password_confirm",
+                      "정말로 이 사용자의 비밀번호를 초기화하시겠습니까? 기존 비밀번호로는 즉시 로그인할 수 없게 됩니다.",
+                    )}
+                  </p>
+                  <div className="flex justify-end gap-2">
+                    <Button variant="ghost" size="sm" onClick={() => setIsPasswordResetOpen(false)}>
+                      {t("ui.common.cancel", "취소")}
+                    </Button>
+                    <Button variant="destructive" size="sm" onClick={confirmGeneratePassword} disabled={resetPasswordMutation.isPending}>
+                      {resetPasswordMutation.isPending && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
+                      {t("ui.admin.users.detail.reset_password", "초기화 및 생성")}
+                    </Button>
+                  </div>
+                </div>
+              )}
+
+              {generatedPassword && (
                 <div className="p-4 border border-dashed rounded-lg bg-yellow-500/5 flex flex-wrap items-center justify-between gap-4">
                   <div className="space-y-1">
                     <p className="text-xs font-bold text-yellow-600 uppercase tracking-wider">
                       Generated Password
                     </p>
                     <p className="font-mono text-lg font-bold">
-                      {watch("password")}
+                      {generatedPassword}
                     </p>
                   </div>
                   <Button size="sm" variant="secondary" onClick={handleCopyPassword}>
diff --git a/backend/internal/handler/user_handler.go b/backend/internal/handler/user_handler.go
index a5ec5e6a..89d68177 100644
--- a/backend/internal/handler/user_handler.go
+++ b/backend/internal/handler/user_handler.go
@@ -322,6 +322,11 @@ func (h *UserHandler) CreateUser(c *fiber.Ctx) error {
 		"grade":           role,
 	}
 
+	// [Override with explicit LoginID if provided]
+	if req.LoginID != "" {
+		attributes["id"] = req.LoginID
+	}
+
 	// [Resolve TenantID and LoginID before Kratos creation]
 	var tenantID string
 	if req.CompanyCode != "" && h.TenantService != nil {
@@ -343,11 +348,6 @@ func (h *UserHandler) CreateUser(c *fiber.Ctx) error {
 		attributes["tenant_id"] = tenantID
 	}
 
-	// [Override with explicit LoginID if provided]
-	if req.LoginID != "" {
-		attributes["id"] = req.LoginID
-	}
-
 	// Merge custom metadata into attributes
 	for k, v := range req.Metadata {
 		// Don't overwrite core fields
@@ -558,7 +558,12 @@ func (h *UserHandler) BulkCreateUsers(c *fiber.Ctx) error {
 			"role":            role,
 		}
 
-		// Sync LoginID from configured custom field
+		// Override with explicit LoginID if provided
+		if item.LoginID != "" {
+			attributes["id"] = item.LoginID
+		}
+
+		// Sync LoginID from configured custom field (overrides explicit LoginID)
 		if tItem.LoginIDField != "" {
 			if val, exists := item.Metadata[tItem.LoginIDField]; exists {
 				if loginIDStr, ok := val.(string); ok && loginIDStr != "" {
@@ -567,11 +572,6 @@ func (h *UserHandler) BulkCreateUsers(c *fiber.Ctx) error {
 			}
 		}
 
-		// Override with explicit LoginID if provided
-		if item.LoginID != "" {
-			attributes["id"] = item.LoginID
-		}
-
 		// Merge metadata
 		for k, v := range item.Metadata {
 			if _, exists := attributes[k]; !exists {
@@ -1151,6 +1151,14 @@ func (h *UserHandler) UpdateUser(c *fiber.Ctx) error {
 		traits["role"] = role
 	}
 
+	// [Override with explicit LoginID if provided]
+	// This is done FIRST so that if a custom loginIdField is configured in the tenant,
+	// the metadata sync below will override this explicit value, preventing the UI's
+	// pre-filled explicit loginId from clobbering the updated custom field.
+	if req.LoginID != nil && *req.LoginID != "" {
+		traits["id"] = *req.LoginID
+	}
+
 	// [LoginID Sync based on Tenant Settings]
 	schemaCompCode := extractTraitString(traits, "companyCode")
 	if req.CompanyCode != nil {
@@ -1177,11 +1185,6 @@ func (h *UserHandler) UpdateUser(c *fiber.Ctx) error {
 		}
 	}
 
-	// [Override with explicit LoginID if provided]
-	if req.LoginID != nil && *req.LoginID != "" {
-		traits["id"] = *req.LoginID
-	}
-
 	// [Namespaced Metadata Sync]
 	coreTraits := map[string]bool{
 		"email": true, "name": true, "phone_number": true,