diff --git a/cmd/main.go b/cmd/main.go
index 7537909..7cca195 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -66,7 +66,7 @@ func main() {
 	groupSvc := group.NewService(groupRepo, userRepo, cacheRepo, &conf.Group, logger.Named("groupSvc"))
 
 	selectionRepo := selection.NewRepository(db)
-	selectionSvc := selection.NewService(selectionRepo, cacheRepo, &conf.Selection, logger.Named("selectionSvc"))
+	selectionSvc := selection.NewService(selectionRepo, groupRepo, cacheRepo, &conf.Selection, logger.Named("selectionSvc"))
 
 	countRepo := count.NewRepository(db)
 	countSvc := count.NewService(countRepo, logger.Named("countSvc"))
diff --git a/internal/group/group.service.go b/internal/group/group.service.go
index 8245603..1eaa595 100644
--- a/internal/group/group.service.go
+++ b/internal/group/group.service.go
@@ -189,6 +189,11 @@ func (s *serviceImpl) DeleteMember(_ context.Context, in *proto.DeleteMemberGrou
 		return nil, err
 	}
 
+	if group.IsConfirmed {
+		s.log.Named("DeleteMember").Error("Group is confirmed", zap.String("user_id", in.UserId))
+		return nil, status.Error(codes.PermissionDenied, "Group is confirmed, so you cannot delete member")
+	}
+
 	if in.LeaderId != group.LeaderID.String() {
 		s.log.Named("DeleteMember").Error("Requested leader_id is not leader of this group", zap.String("leader_id", in.LeaderId))
 		return nil, status.Error(codes.PermissionDenied, "requested leader_id is not leader of this group")
@@ -263,6 +268,11 @@ func (s *serviceImpl) Leave(_ context.Context, in *proto.LeaveGroupRequest) (*pr
 		return nil, err
 	}
 
+	if group.IsConfirmed {
+		s.log.Named("Leave").Error("Group is confirmed", zap.String("user_id", in.UserId))
+		return nil, status.Error(codes.PermissionDenied, "Group is confirmed, so you cannot leave")
+	}
+
 	if in.UserId == group.LeaderID.String() {
 		s.log.Named("Leave").Error("User is the leader of the group", zap.String("user_id", in.UserId))
 		return nil, status.Error(codes.PermissionDenied, "You are the group leader, so you cannot leave")
@@ -328,6 +338,17 @@ func (s *serviceImpl) Leave(_ context.Context, in *proto.LeaveGroupRequest) (*pr
 }
 
 func (s *serviceImpl) Join(_ context.Context, in *proto.JoinGroupRequest) (*proto.JoinGroupResponse, error) {
+	group, err := s.findByUserId(in.UserId)
+	if err != nil {
+		s.log.Named("Join").Error("findByUserId group: ", zap.Error(err))
+		return nil, err
+	}
+
+	if group.IsConfirmed {
+		s.log.Named("Join").Error("Group is confirmed", zap.String("user_id", in.UserId))
+		return nil, status.Error(codes.PermissionDenied, "Group is confirmed, so you cannot leave to join other groups")
+	}
+
 	joiningGroup := &model.Group{}
 	if err := s.repo.FindByToken(in.Token, joiningGroup); err != nil {
 		s.log.Named("Join").Error("FindByToken joiningGroup TX: ", zap.Error(err))
diff --git a/internal/selection/selection.service.go b/internal/selection/selection.service.go
index 58c2098..6822433 100644
--- a/internal/selection/selection.service.go
+++ b/internal/selection/selection.service.go
@@ -7,6 +7,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/isd-sgcu/rpkm67-backend/config"
 	"github.com/isd-sgcu/rpkm67-backend/internal/cache"
+	"github.com/isd-sgcu/rpkm67-backend/internal/group"
 	proto "github.com/isd-sgcu/rpkm67-go-proto/rpkm67/backend/selection/v1"
 	"github.com/isd-sgcu/rpkm67-model/model"
 	"go.uber.org/zap"
@@ -20,22 +21,34 @@ type Service interface {
 
 type serviceImpl struct {
 	proto.UnimplementedSelectionServiceServer
-	repo  Repository
-	cache cache.Repository
-	conf  *config.SelectionConfig
-	log   *zap.Logger
+	repo      Repository
+	groupRepo group.Repository
+	cache     cache.Repository
+	conf      *config.SelectionConfig
+	log       *zap.Logger
 }
 
-func NewService(repo Repository, cache cache.Repository, conf *config.SelectionConfig, log *zap.Logger) Service {
+func NewService(repo Repository, groupRepo group.Repository, cache cache.Repository, conf *config.SelectionConfig, log *zap.Logger) Service {
 	return &serviceImpl{
-		repo:  repo,
-		cache: cache,
-		conf:  conf,
-		log:   log,
+		repo:      repo,
+		groupRepo: groupRepo,
+		cache:     cache,
+		conf:      conf,
+		log:       log,
 	}
 }
 
 func (s *serviceImpl) Create(ctx context.Context, in *proto.CreateSelectionRequest) (*proto.CreateSelectionResponse, error) {
+	isConfirmed, err := s.isGroupConfirmed(in.GroupId)
+	if err != nil {
+		s.log.Named("Create").Error(fmt.Sprintf("isGroupConfirmed: group_id=%s", in.GroupId), zap.Error(err))
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+	if isConfirmed {
+		s.log.Named("Create").Error(fmt.Sprintf("Failed to create selection: group_id=%s", in.GroupId), zap.Error(err))
+		return nil, status.Error(codes.InvalidArgument, "Group is confirmed, cannot create selection")
+	}
+
 	groupUUID, err := uuid.Parse(in.GroupId)
 	if err != nil {
 		s.log.Named("Create").Error(fmt.Sprintf("Parse group id: %s", in.GroupId), zap.Error(err))
@@ -130,7 +143,17 @@ func (s *serviceImpl) FindByGroupId(ctx context.Context, in *proto.FindByGroupId
 }
 
 func (s *serviceImpl) Delete(ctx context.Context, in *proto.DeleteSelectionRequest) (*proto.DeleteSelectionResponse, error) {
-	err := s.repo.Delete(in.GroupId, in.BaanId)
+	isConfirmed, err := s.isGroupConfirmed(in.GroupId)
+	if err != nil {
+		s.log.Named("Create").Error(fmt.Sprintf("isGroupConfirmed: group_id=%s", in.GroupId), zap.Error(err))
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+	if isConfirmed {
+		s.log.Named("Create").Error(fmt.Sprintf("Failed to create selection: group_id=%s", in.GroupId), zap.Error(err))
+		return nil, status.Error(codes.InvalidArgument, "Group is confirmed, cannot delete selection")
+	}
+
+	err = s.repo.Delete(in.GroupId, in.BaanId)
 	if err != nil {
 		s.log.Named("Delete").Error(fmt.Sprintf("Delete: group_id=%s, baan_id=%s", in.GroupId, in.BaanId), zap.Error(err))
 		return nil, status.Error(codes.Internal, err.Error())
@@ -184,9 +207,19 @@ func (s *serviceImpl) CountByBaanId(ctx context.Context, in *proto.CountByBaanId
 }
 
 func (s *serviceImpl) Update(ctx context.Context, in *proto.UpdateSelectionRequest) (*proto.UpdateSelectionResponse, error) {
+	isConfirmed, err := s.isGroupConfirmed(in.GroupId)
+	if err != nil {
+		s.log.Named("Create").Error(fmt.Sprintf("isGroupConfirmed: group_id=%s", in.GroupId), zap.Error(err))
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+	if isConfirmed {
+		s.log.Named("Create").Error(fmt.Sprintf("Failed to create selection: group_id=%s", in.GroupId), zap.Error(err))
+		return nil, status.Error(codes.InvalidArgument, "Group is confirmed, cannot update selection")
+	}
+
 	oldSelections := &[]model.Selection{}
 
-	err := s.repo.FindByGroupId(in.GroupId, oldSelections)
+	err = s.repo.FindByGroupId(in.GroupId, oldSelections)
 	if err != nil {
 		s.log.Named("Update").Error(fmt.Sprintf("FindByGroupId: group_id=%s", in.GroupId), zap.Error(err))
 		return nil, status.Error(codes.Internal, err.Error())
@@ -254,3 +287,13 @@ func (s *serviceImpl) Update(ctx context.Context, in *proto.UpdateSelectionReque
 
 	return &res, nil
 }
+
+func (s *serviceImpl) isGroupConfirmed(groupID string) (bool, error) {
+	group := &model.Group{}
+	if err := s.groupRepo.FindOne(groupID, group); err != nil {
+		s.log.Named("isGroupConfirmed").Error(fmt.Sprintf("FindOne: group_id=%s", groupID), zap.Error(err))
+		return false, err
+	}
+
+	return group.IsConfirmed, nil
+}