diff --git a/config/host.go b/config/host.go
index b8d3f83..b63a1cf 100644
--- a/config/host.go
+++ b/config/host.go
@@ -17,6 +17,7 @@ type Host struct {
 }
 
 type HostItem struct {
+	Name       string
 	CalendarId string
 	// Price is the daily price in EUR
 	Price float64
@@ -41,6 +42,7 @@ func NewHost() *Host {
 		Platforms:      []string{"Booking", "AirBnb", "TripAdvisor", "Other"}, // TODO: add to DB
 		Items: map[string]HostItem{ // TODO: move to DB
 			"T2": {
+				Name:             "T2",
 				Price:            59.0,
 				CalendarId:       os.Getenv("CALENDAR_ID_T2"),
 				MustSyncCalendar: true,
@@ -49,6 +51,7 @@ func NewHost() *Host {
 			},
 
 			"T3": {
+				Name:             "T3",
 				Price:            80.0,
 				CalendarId:       os.Getenv("CALENDAR_ID_T3"),
 				MustSyncCalendar: true,
@@ -56,15 +59,19 @@ func NewHost() *Host {
 				Taxable:          true,
 			},
 			"Airport": {
+				Name:  "Airport",
 				Price: 25.0,
 			},
 			"Port": {
+				Name:  "Port",
 				Price: 20.0,
 			},
 			"Transport": {
+				Name:  "Transport",
 				Price: 20.0,
 			},
 			"Taxes": { // TODO: remove after auto creation enabled
+				Name:  "Taxes",
 				Price: 1.5,
 			},
 		},
diff --git a/internal/calendar/option.go b/internal/calendar/option.go
index 5ac7438..e7bb6e6 100644
--- a/internal/calendar/option.go
+++ b/internal/calendar/option.go
@@ -1,18 +1,3 @@
 package calendar
 
-import (
-	"fmt"
-)
-
 type Option func(*Service) error
-
-func WithCalendar(key string, calendarId string) Option {
-	return func(s *Service) error {
-		_, err := s.CalendarList.Get(calendarId).Do()
-		if err != nil {
-			return fmt.Errorf("cannot find calendar entry with id %q: %w", calendarId, err)
-		}
-		s.calIds[key] = calendarId
-		return nil
-	}
-}
diff --git a/internal/calendar/service.go b/internal/calendar/service.go
index 0d3b826..22d1b72 100644
--- a/internal/calendar/service.go
+++ b/internal/calendar/service.go
@@ -19,7 +19,7 @@ import (
 const tokFile = "token.json"
 
 type Service struct {
-	calIds map[string]string
+	calIds map[string]struct{}
 	*calendar.Service
 }
 
@@ -39,7 +39,7 @@ func NewService(ctx context.Context, credJson string, opts ...Option) (*Service,
 
 	s := &Service{
 		Service: srv,
-		calIds:  make(map[string]string),
+		calIds:  make(map[string]struct{}),
 	}
 
 	for _, opt := range opts {
@@ -53,6 +53,16 @@ func NewService(ctx context.Context, credJson string, opts ...Option) (*Service,
 }
 
 func (s *Service) Create(calendarId, name, description string, from, to time.Time) error {
+	// add calendarId to list of known calendars
+	_, ok := s.calIds[calendarId]
+	if !ok {
+		_, err := s.CalendarList.Get(calendarId).Do()
+		if err != nil {
+			return fmt.Errorf("cannot find calendar entry with id %q: %w", calendarId, err)
+		}
+		s.calIds[calendarId] = struct{}{}
+	}
+
 	ne, err := s.Events.Insert(calendarId, &calendar.Event{
 		Description: name,
 		End: &calendar.EventDateTime{
diff --git a/internal/server/handle_bookings.go b/internal/server/handle_bookings.go
index 8a7fb82..c052999 100644
--- a/internal/server/handle_bookings.go
+++ b/internal/server/handle_bookings.go
@@ -2,7 +2,6 @@ package server
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -129,8 +128,15 @@ func handleBookingPage(bs *booking.Service, hc *config.Host) echo.HandlerFunc {
 			Total: strconv.FormatFloat(u.Reduce(b.Items, func(i booking.Item, sum float64) float64 {
 				return sum + i.Price*float64(i.Quantity)
 			}, 0.0), 'f', 2, 64),
-			Platforms:      hc.Platforms,
-			ItemList:       u.Map(hc.Items, func(i config.HostItem) string { return i.Name }),
+			Platforms: hc.Platforms,
+			ItemList: u.OrderBy(func(items map[string]config.HostItem) (out []string) {
+				for _, item := range items {
+					out = append(out, item.Name)
+				}
+				return out
+			}(hc.Items),
+				func(l, r string) bool { return l < r },
+			),
 			PaymentMethods: hc.PaymentMethods,
 		}
 		return renderTempl(c, http.StatusOK, view.BookingById(bvm))
@@ -142,11 +148,11 @@ func handleBookingUpdate(bs *booking.Service, hc *config.Host) echo.HandlerFunc
 		type UpdateBooking struct {
 			From           time.Time `json:"from"`
 			To             time.Time `json:"to"`
+			ExternalId     *string   `form:"external_id"`
 			Name           string    `form:"name"`
 			PhoneNumber    string    `form:"phone_number"`
 			Email          string    `form:"email"`
 			Platform       string    `form:"platform"`
-			ExternalId     *string   `form:"external_id"`
 			Id             int       `param:"id"`
 			CustomerNumber int       `form:"customer_number"`
 			PlatformFees   float64   `form:"platform_fees"`
@@ -238,7 +244,7 @@ func handleCreateItem(bs *booking.Service, cs *calendar.Service, hc *config.Host
 
 		itm, ok := hc.Items[ni.Item]
 		if !ok {
-			return errors.New(fmt.Sprintf("invalid item name %q", ni.Item))
+			return fmt.Errorf("invalid item name %q", ni.Item)
 		}
 
 		i := bs.CreateItem(b.Id, ni.Item, ni.Quantity, ni.Price, ni.PaymentMethod)
diff --git a/internal/server/routes.go b/internal/server/routes.go
index d1848da..51dff6a 100644
--- a/internal/server/routes.go
+++ b/internal/server/routes.go
@@ -32,7 +32,7 @@ func (s Server) MountHandlers() {
 	g.GET("/bookings/:id", handleBookingPage(s.bs, s.hc))
 	g.PUT("/bookings/:id", handleBookingUpdate(s.bs, s.hc))
 	g.PATCH("/bookings/:id/cancel", handleBookingCancel(s.bs))
-	g.POST("/bookings/:id/items", handleCreateItem(s.bs))
+	g.POST("/bookings/:id/items", handleCreateItem(s.bs, s.cs, s.hc))
 	g.POST("/items/:id", handleItemPay(s.bs))
 	g.PUT("/items/:id", handleItemUpdate(s.bs))
 	g.GET("/items/:id", handleLineItemForm(s.bs))