diff --git a/backend/app/http/v1/user.go b/backend/app/http/v1/user.go
index ecde09c..f38b9cf 100644
--- a/backend/app/http/v1/user.go
+++ b/backend/app/http/v1/user.go
@@ -316,5 +316,6 @@ func (u *User) MarkAllNotificationsRead(ctx fiber.Ctx, user *models.User) error
 // @Bind user local key(__ctx_user)
 // @Bind status query
 func (u *User) MyCoupons(ctx fiber.Ctx, user *models.User, status string) ([]dto.UserCouponItem, error) {
-	return services.Coupon.ListUserCoupons(ctx, user.ID, status)
+	tenantID := getTenantID(ctx)
+	return services.Coupon.ListUserCoupons(ctx, tenantID, user.ID, status)
 }
diff --git a/backend/app/services/coupon.go b/backend/app/services/coupon.go
index aacc1e2..bb23fb8 100644
--- a/backend/app/services/coupon.go
+++ b/backend/app/services/coupon.go
@@ -2,11 +2,14 @@ package services
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"quyun/v2/app/errorx"
 	coupon_dto "quyun/v2/app/http/v1/dto"
 	"quyun/v2/database/models"
+
+	"gorm.io/gorm"
 )
 
 // @provider
@@ -14,6 +17,7 @@ type coupon struct{}
 
 func (s *coupon) ListUserCoupons(
 	ctx context.Context,
+	tenantID int64,
 	userID int64,
 	status string,
 ) ([]coupon_dto.UserCouponItem, error) {
@@ -32,11 +36,41 @@ func (s *coupon) ListUserCoupons(
 	if err != nil {
 		return nil, errorx.ErrDatabaseError.WithCause(err)
 	}
+	if len(list) == 0 {
+		return []coupon_dto.UserCouponItem{}, nil
+	}
 
-	var res []coupon_dto.UserCouponItem
+	couponIDSet := make(map[int64]struct{}, len(list))
+	couponIDs := make([]int64, 0, len(list))
 	for _, v := range list {
-		c, _ := models.CouponQuery.WithContext(ctx).Where(models.CouponQuery.ID.Eq(v.CouponID)).First()
+		if _, ok := couponIDSet[v.CouponID]; ok {
+			continue
+		}
+		couponIDs = append(couponIDs, v.CouponID)
+		couponIDSet[v.CouponID] = struct{}{}
+	}
 
+	cTbl, cQ := models.CouponQuery.QueryContext(ctx)
+	cQ = cQ.Where(cTbl.ID.In(couponIDs...))
+	if tenantID > 0 {
+		cQ = cQ.Where(cTbl.TenantID.Eq(tenantID))
+	}
+	coupons, err := cQ.Find()
+	if err != nil {
+		return nil, errorx.ErrDatabaseError.WithCause(err)
+	}
+
+	couponMap := make(map[int64]*models.Coupon, len(coupons))
+	for _, c := range coupons {
+		couponMap[c.ID] = c
+	}
+
+	res := make([]coupon_dto.UserCouponItem, 0, len(list))
+	for _, v := range list {
+		c, ok := couponMap[v.CouponID]
+		if !ok {
+			continue
+		}
 		item := coupon_dto.UserCouponItem{
 			ID:       v.ID,
 			CouponID: v.CouponID,
@@ -61,7 +95,7 @@ func (s *coupon) ListUserCoupons(
 }
 
 // Validate checks if a coupon can be used for an order and returns the discount amount
-func (s *coupon) Validate(ctx context.Context, userID, userCouponID, amount int64) (int64, error) {
+func (s *coupon) Validate(ctx context.Context, tenantID, userID, userCouponID, amount int64) (int64, error) {
 	uc, err := models.UserCouponQuery.WithContext(ctx).Where(models.UserCouponQuery.ID.Eq(userCouponID)).First()
 	if err != nil {
 		return 0, errorx.ErrRecordNotFound.WithMsg("优惠券不存在")
@@ -77,6 +111,9 @@ func (s *coupon) Validate(ctx context.Context, userID, userCouponID, amount int6
 	if err != nil {
 		return 0, errorx.ErrRecordNotFound.WithMsg("优惠券信息缺失")
 	}
+	if tenantID > 0 && c.TenantID != tenantID {
+		return 0, errorx.ErrForbidden.WithMsg("优惠券租户不匹配")
+	}
 
 	now := time.Now()
 	if !c.StartAt.IsZero() && now.Before(c.StartAt) {
@@ -109,7 +146,29 @@ func (s *coupon) Validate(ctx context.Context, userID, userCouponID, amount int6
 }
 
 // MarkUsed marks a user coupon as used (intended to be called inside a transaction)
-func (s *coupon) MarkUsed(ctx context.Context, tx *models.Query, userCouponID, orderID int64) error {
+func (s *coupon) MarkUsed(ctx context.Context, tx *models.Query, tenantID, userCouponID, orderID int64) error {
+	uc, err := tx.UserCoupon.WithContext(ctx).Where(tx.UserCoupon.ID.Eq(userCouponID)).First()
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return errorx.ErrRecordNotFound.WithMsg("优惠券不存在")
+		}
+		return errorx.ErrDatabaseError.WithCause(err)
+	}
+	if uc.Status != "unused" {
+		return errorx.ErrBusinessLogic.WithMsg("优惠券核销失败")
+	}
+
+	c, err := tx.Coupon.WithContext(ctx).Where(tx.Coupon.ID.Eq(uc.CouponID)).First()
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return errorx.ErrRecordNotFound.WithMsg("优惠券信息缺失")
+		}
+		return errorx.ErrDatabaseError.WithCause(err)
+	}
+	if tenantID > 0 && c.TenantID != tenantID {
+		return errorx.ErrForbidden.WithMsg("优惠券租户不匹配")
+	}
+
 	now := time.Now()
 	// Update User Coupon
 	info, err := tx.UserCoupon.WithContext(ctx).
@@ -127,8 +186,6 @@ func (s *coupon) MarkUsed(ctx context.Context, tx *models.Query, userCouponID, o
 	}
 
 	// Update Coupon used quantity (Optional, but good for stats)
-	// We need CouponID from uc
-	uc, _ := tx.UserCoupon.WithContext(ctx).Where(tx.UserCoupon.ID.Eq(userCouponID)).First()
 	_, _ = tx.Coupon.WithContext(ctx).Where(tx.Coupon.ID.Eq(uc.CouponID)).UpdateSimple(tx.Coupon.UsedQuantity.Add(1))
 
 	return nil
diff --git a/backend/app/services/coupon_test.go b/backend/app/services/coupon_test.go
index 84121b1..8f5f71b 100644
--- a/backend/app/services/coupon_test.go
+++ b/backend/app/services/coupon_test.go
@@ -56,6 +56,7 @@ func (s *CouponTestSuite) Test_CouponFlow() {
 
 		// 1. Create Coupon (Fixed 5.00 CNY, Min 10.00 CNY)
 		cp := &models.Coupon{
+			TenantID:       tenantID,
 			Title:          "Save 5",
 			Type:           "fix_amount",
 			Value:          500,
@@ -72,13 +73,13 @@ func (s *CouponTestSuite) Test_CouponFlow() {
 		models.UserCouponQuery.WithContext(ctx).Create(uc)
 
 		Convey("should validate coupon successfully", func() {
-			discount, err := Coupon.Validate(ctx, user.ID, uc.ID, 1500)
+			discount, err := Coupon.Validate(ctx, tenantID, user.ID, uc.ID, 1500)
 			So(err, ShouldBeNil)
 			So(discount, ShouldEqual, 500)
 		})
 
 		Convey("should fail if below min amount", func() {
-			_, err := Coupon.Validate(ctx, user.ID, uc.ID, 800)
+			_, err := Coupon.Validate(ctx, tenantID, user.ID, uc.ID, 800)
 			So(err, ShouldNotBeNil)
 		})
 
diff --git a/backend/app/services/order.go b/backend/app/services/order.go
index 45f3739..1322bb1 100644
--- a/backend/app/services/order.go
+++ b/backend/app/services/order.go
@@ -136,7 +136,7 @@ func (s *order) Create(
 
 	// Validate Coupon
 	if form.UserCouponID > 0 {
-		discount, err := Coupon.Validate(ctx, uid, form.UserCouponID, amountOriginal)
+		discount, err := Coupon.Validate(ctx, tenantID, uid, form.UserCouponID, amountOriginal)
 		if err != nil {
 			return nil, err
 		}
@@ -188,7 +188,7 @@ func (s *order) Create(
 
 		// Mark Coupon Used
 		if form.UserCouponID > 0 {
-			if err := Coupon.MarkUsed(ctx, tx, form.UserCouponID, order.ID); err != nil {
+			if err := Coupon.MarkUsed(ctx, tx, tenantID, form.UserCouponID, order.ID); err != nil {
 				return err
 			}
 		}
diff --git a/backend/app/services/user.go b/backend/app/services/user.go
index a763f97..74a4934 100644
--- a/backend/app/services/user.go
+++ b/backend/app/services/user.go
@@ -160,9 +160,12 @@ func (s *user) RealName(ctx context.Context, userID int64, form *user_dto.RealNa
 }
 
 // GetNotifications 获取通知
-func (s *user) GetNotifications(ctx context.Context, userID int64, typeArg string) ([]user_dto.Notification, error) {
+func (s *user) GetNotifications(ctx context.Context, tenantID, userID int64, typeArg string) ([]user_dto.Notification, error) {
 	tbl, query := models.NotificationQuery.QueryContext(ctx)
 	query = query.Where(tbl.UserID.Eq(userID))
+	if tenantID > 0 {
+		query = query.Where(tbl.TenantID.Eq(tenantID))
+	}
 	if typeArg != "" && typeArg != "all" {
 		query = query.Where(tbl.Type.Eq(typeArg))
 	}
diff --git a/backend/app/services/user_test.go b/backend/app/services/user_test.go
index 60d1511..ec4e3be 100644
--- a/backend/app/services/user_test.go
+++ b/backend/app/services/user_test.go
@@ -171,15 +171,16 @@ func (s *UserTestSuite) Test_GetNotifications() {
 
 		// Mock notifications
 		_ = models.Q.Notification.WithContext(ctx).Create(&models.Notification{
-			UserID:  userID,
-			Type:    "system",
-			Title:   "Welcome",
-			Content: "Hello World",
-			IsRead:  false,
+			TenantID: tenantID,
+			UserID:   userID,
+			Type:     "system",
+			Title:    "Welcome",
+			Content:  "Hello World",
+			IsRead:   false,
 		})
 
 		Convey("should return notifications", func() {
-			list, err := User.GetNotifications(ctx, userID, "all")
+			list, err := User.GetNotifications(ctx, tenantID, userID, "all")
 			So(err, ShouldBeNil)
 			So(len(list), ShouldEqual, 1)
 			So(list[0].Title, ShouldEqual, "Welcome")