diff --git a/src/BusProNet/DataProcessor/BookingDataProcessor.php b/src/BusProNet/DataProcessor/BookingDataProcessor.php
index 13c2633..ecebed2 100644
--- a/src/BusProNet/DataProcessor/BookingDataProcessor.php
+++ b/src/BusProNet/DataProcessor/BookingDataProcessor.php
@@ -33,26 +33,33 @@ class BookingDataProcessor
                 ...$participant->rentalInsurance,
             ];
             foreach ($servicesToMap as $service) {
-                if (false === isset($this->additionalServices[$service->id])) {
-                    $serviceToAdd = $travelData->additionalServices[$service->id];
+                if (false === isset($bookingData->additionalServices[$service->id])) {
+                    $serviceToAdd = $travelData->additionalServices[$service->id] ?? null;
                     if (null !== $serviceToAdd) {
                         $bookingData->additionalServices[$service->id] = $serviceToAdd;
                         $bookingData->additionalServices[$service->id]->individualPrice[$participant->index] = $serviceToAdd->price;
                     }
                 }
-                $bookingData->additionalServices[$service->id]->mapping[] = $participant->index;
+                if (true === isset($bookingData->additionalServices[$service->id])) {
+                    $bookingData->additionalServices[$service->id]->mapping[] = $participant->index;
+                }
             }
             foreach ([$participant->transportationServiceTo, $participant->transportationServiceFro] as $service) {
-                if (false === isset($this->transportationServices[$service->id])) {
-                    $serviceToAdd = $travelData->transportationServices[$service->id];
+                if (null === $service) {
+                    continue;
+                }
+                if (false === isset($bookingData->transportationServices[$service->id])) {
+                    $serviceToAdd = $travelData->transportationServices[$service->id] ?? null;
                     if (null !== $serviceToAdd) {
                         $bookingData->transportationServices[$service->id] = $serviceToAdd;
                         $bookingData->transportationServices[$service->id]->individualPrice[$participant->index] = $serviceToAdd->price;
                     }
                 }
-                $bookingData->transportationServices[$service->id]->mapping[] = $participant->index;
+                if (true === isset($bookingData->transportationServices[$service->id])) {
+                    $bookingData->transportationServices[$service->id]->mapping[] = $participant->index;
+                }
             }
-            if ('BUS' === $participant->transportationServiceTo->subType && null !== $selectedPickup = $participant->pickup) {
+            if ('BUS' === $participant->transportationServiceTo?->subType && null !== $selectedPickup = $participant->pickup) {
                 if (false === isset($bookingData->pickupsTo[$selectedPickup->id])) {
                     $bookingData->pickupsTo[$selectedPickup->id] = $selectedPickup;
                 }