diff --git a/modules/market_management/mcp.php b/modules/market_management/mcp.php
index 28006e6..4b751c2 100644
--- a/modules/market_management/mcp.php
+++ b/modules/market_management/mcp.php
@@ -215,6 +215,7 @@ function market_management_mcp_get_market(PDO $pdo, int $marketId, bool $include
 
 function market_management_mcp_update_occurrence(PDO $pdo, int $occurrenceId, array $input): array
 {
+    unset($input['occurrence_id']);
     $simpleCostFields = [];
     foreach (['gross_cost', 'cost_items_text', 'tax_status', 'tax_rate'] as $field) {
         if (array_key_exists($field, $input)) {
diff --git a/modules/market_management/service.php b/modules/market_management/service.php
index b3a1698..c4ef701 100644
--- a/modules/market_management/service.php
+++ b/modules/market_management/service.php
@@ -775,16 +775,21 @@ function market_management_create_occurrence(PDO $pdo, array $input): array
         }
         market_management_set_occurrence_contact($pdo, [
             'occurrence_id' => (int) $occurrence['id'],
-            'contact_person_name' => null,
-            'contact_email' => null,
-            'contact_phone' => null,
+            'contact_person_name' => $input['contact_person_name'] ?? null,
+            'contact_email' => $input['contact_email'] ?? null,
+            'contact_phone' => $input['contact_phone'] ?? null,
         ]);
+        $grossCost = market_management_optional_number($input, 'gross_cost') ?? '0.00';
+        $taxStatus = trim((string) ($input['tax_status'] ?? 'taxable'));
+        $taxRate = market_management_optional_number($input, 'tax_rate')
+            ?? ($taxStatus === 'tax_free' ? '0.00' : '8.10');
         market_management_create_cost_item($pdo, [
             'occurrence_id' => (int) $occurrence['id'],
             'cost_type_id' => market_management_get_cost_type_id($pdo, 'stand_fee'),
-            'gross_amount' => 0,
-            'tax_status' => 'taxable',
-            'tax_rate' => 8.10,
+            'description' => market_management_optional_string($input, 'cost_items_text'),
+            'gross_amount' => $grossCost,
+            'tax_status' => $taxStatus,
+            'tax_rate' => $taxRate,
         ]);
         if ($startedTransaction) {
             $pdo->commit();