diff --git a/module/Finna/src/Finna/ILS/Driver/Alma.php b/module/Finna/src/Finna/ILS/Driver/Alma.php
index 82c319c95cc..7aa78fe4ee7 100644
--- a/module/Finna/src/Finna/ILS/Driver/Alma.php
+++ b/module/Finna/src/Finna/ILS/Driver/Alma.php
@@ -2031,10 +2031,11 @@ public function getHolding($id, $patron = null, array $options = [])
                     $this->config['Holdings']['externalInterfaceUrl'] ?? ''
                 );
                 $summary = [
+                    'id' => $id,
                     'available' => $items['available'],
                     'total' => $items['total'],
                     'availability' => null,
-                    'callnumber' => null,
+                    'callnumber' => '',
                     'location' => '__HOLDINGSSUMMARYLOCATION__',
                     'externalInterfaceUrl' => $externalInterfaceUrl,
                 ];
@@ -2160,11 +2161,12 @@ public function getHolding($id, $patron = null, array $options = [])
 
                 // Add summary
                 $summary = [
+                    'id' => $id,
                     'available' => $totalAvailable,
                     'total' => $total,
                     'locations' => count($locations),
                     'availability' => null,
-                    'callnumber' => null,
+                    'callnumber' => '',
                     'location' => '__HOLDINGSSUMMARYLOCATION__',
                 ];
                 if ($displayRequests) {
@@ -2841,12 +2843,13 @@ protected function getStatusesForInventoryTypes($ids, $types)
                     // we need to add a few dummy-fields that VuFind expects to be
                     // defined for all elements.
                     $summary = [
+                        'id' => (string)$bib->mms_id,
                         'available' => $itemsAvailable,
                         'total' => $itemsTotal,
                         'ordered' => $itemsOrdered,
                         'locations' => count(array_unique(array_column($status, 'location'))),
                         'availability' => null,
-                        'callnumber' => null,
+                        'callnumber' => '',
                         'location' => '__HOLDINGSSUMMARYLOCATION__',
                         'externalInterfaceUrl' => $externalInterfaceUrl,
                     ];
diff --git a/module/Finna/src/Finna/ILS/Driver/AxiellWebServices.php b/module/Finna/src/Finna/ILS/Driver/AxiellWebServices.php
index 290e8467b93..7c6220d474f 100644
--- a/module/Finna/src/Finna/ILS/Driver/AxiellWebServices.php
+++ b/module/Finna/src/Finna/ILS/Driver/AxiellWebServices.php
@@ -198,14 +198,14 @@ class AxiellWebServices extends \VuFind\ILS\Driver\AbstractBase implements
     /**
      * Institution settings for the order of organisations
      *
-     * @var string
+     * @var array
      */
     protected $holdingsOrganisationOrder;
 
     /**
      * Institution settings for the order of branches
      *
-     * @var string
+     * @var array
      */
     protected $holdingsBranchOrder;
 
@@ -1108,7 +1108,7 @@ public function getHolding($id, array $patron = null, array $options = [])
         if (!empty($result)) {
             usort($result, [$this, 'holdingsSortFunction']);
 
-            $summary = $this->getHoldingsSummary($result);
+            $summary = $this->getHoldingsSummary($result, $id);
             $result[] = $summary;
         }
 
@@ -1273,11 +1273,12 @@ protected function parseHoldings($organisationHoldings, $id, $journalInfo = null
     /**
      * Return summary of holdings items.
      *
-     * @param array $holdings Parsed holdings items
+     * @param array  $holdings Parsed holdings items
+     * @param string $id       Record id
      *
      * @return array summary
      */
-    protected function getHoldingsSummary($holdings)
+    protected function getHoldingsSummary($holdings, $id)
     {
         $holdable = false;
         $journal = isset($holdings[0]['journalInfo']);
@@ -1315,15 +1316,16 @@ protected function getHoldingsSummary($holdings)
         // we need to add a few dummy-fields that VuFind expects to be
         // defined for all elements.
         return [
-           'available' => $availableTotal,
-           'ordered' => $orderedTotal,
-           'total' => $itemsTotal - $orderedTotal,
-           'reservations' => $reservationsTotal,
-           'locations' => count($locations),
-           'holdable' => $holdable,
-           'availability' => null,
-           'callnumber' => '',
-           'location' => '__HOLDINGSSUMMARYLOCATION__',
+            'id' => $id,
+            'available' => $availableTotal,
+            'ordered' => $orderedTotal,
+            'total' => $itemsTotal - $orderedTotal,
+            'reservations' => $reservationsTotal,
+            'locations' => count($locations),
+            'holdable' => $holdable,
+            'availability' => null,
+            'callnumber' => '',
+            'location' => '__HOLDINGSSUMMARYLOCATION__',
         ];
     }
 
diff --git a/module/Finna/src/Finna/ILS/Driver/Demo.php b/module/Finna/src/Finna/ILS/Driver/Demo.php
index a801ac8d4c6..25f88c13fdc 100644
--- a/module/Finna/src/Finna/ILS/Driver/Demo.php
+++ b/module/Finna/src/Finna/ILS/Driver/Demo.php
@@ -109,7 +109,7 @@ public function getStatus($id)
     {
         $result = parent::getStatus($id);
         if (!empty($result)) {
-            $result[] = $this->getHoldingsSummary($result);
+            $result[] = $this->getHoldingsSummary($result, $id);
         }
         return $result;
     }
@@ -132,7 +132,7 @@ public function getHolding($id, array $patron = null, array $options = [])
     {
         $result = parent::getHolding($id, $patron, $options);
         if (!empty($result['holdings'])) {
-            $result['holdings'][] = $this->getHoldingsSummary($result['holdings']);
+            $result['holdings'][] = $this->getHoldingsSummary($result['holdings'], $id);
         }
         return $result;
     }
@@ -484,11 +484,12 @@ protected function pickUpLocationIsValid($pickUpLocation, $patron, $holdDetails)
     /**
      * Return summary of holdings items.
      *
-     * @param array $holdings Parsed holdings items
+     * @param array  $holdings Parsed holdings items
+     * @param string $id       Record id
      *
      * @return array summary
      */
-    protected function getHoldingsSummary($holdings)
+    protected function getHoldingsSummary($holdings, $id)
     {
         $availableTotal = $itemsTotal = 0;
         $requests = 0;
@@ -512,14 +513,15 @@ protected function getHoldingsSummary($holdings)
         // Use a stupid location name to make sure this doesn't get mixed with
         // real items that don't have a proper location.
         $result = [
-           'available' => $availableTotal,
-           'total' => $itemsTotal,
-           'locations' => count($locations),
-           'availability' => null,
-           'callnumber' => null,
-           'location' => '__HOLDINGSSUMMARYLOCATION__',
-           'reservations' => rand(0, 8),
-           'ordered' => rand(0, 20),
+            'id' => $id,
+            'available' => $availableTotal,
+            'total' => $itemsTotal,
+            'locations' => count($locations),
+            'availability' => null,
+            'callnumber' => '',
+            'location' => '__HOLDINGSSUMMARYLOCATION__',
+            'reservations' => rand(0, 8),
+            'ordered' => rand(0, 20),
         ];
         return $result;
     }
diff --git a/module/Finna/src/Finna/ILS/Driver/KohaRest.php b/module/Finna/src/Finna/ILS/Driver/KohaRest.php
index bcd116d1007..a220c54b9d1 100644
--- a/module/Finna/src/Finna/ILS/Driver/KohaRest.php
+++ b/module/Finna/src/Finna/ILS/Driver/KohaRest.php
@@ -1333,13 +1333,14 @@ protected function getItemStatusesForBiblio($id, $patron = null, $brief = false)
 
         // Add summary
         $summary = [
-           'available' => $availableTotal,
-           'total' => $itemsTotal,
-           'ordered' => $orderedTotal,
-           'locations' => count(array_unique(array_column($statuses, 'location'))),
-           'availability' => null,
-           'callnumber' => null,
-           'location' => '__HOLDINGSSUMMARYLOCATION__',
+            'id' => $id,
+            'available' => $availableTotal,
+            'total' => $itemsTotal,
+            'ordered' => $orderedTotal,
+            'locations' => count(array_unique(array_column($statuses, 'location'))),
+            'availability' => null,
+            'callnumber' => '',
+            'location' => '__HOLDINGSSUMMARYLOCATION__',
         ];
         if (!empty($this->config['Holdings']['display_total_hold_count'])) {
             $summary['reservations'] = $requestsTotal;
diff --git a/module/Finna/src/Finna/ILS/Driver/KohaRestSuomi.php b/module/Finna/src/Finna/ILS/Driver/KohaRestSuomi.php
index 17d524693ad..59334d9b8f6 100644
--- a/module/Finna/src/Finna/ILS/Driver/KohaRestSuomi.php
+++ b/module/Finna/src/Finna/ILS/Driver/KohaRestSuomi.php
@@ -153,7 +153,7 @@ public function getHolding($id, array $patron = null, array $options = [])
     {
         $data = parent::getHolding($id, $patron);
         if (!empty($data['holdings'])) {
-            $summary = $this->getHoldingsSummary($data['holdings']);
+            $summary = $this->getHoldingsSummary($data['holdings'], $id);
 
             // Remove request counts before adding the summary if necessary
             if (
@@ -185,7 +185,7 @@ public function getStatus($id)
     {
         $data = parent::getStatus($id);
         if (!empty($data)) {
-            $summary = $this->getHoldingsSummary($data);
+            $summary = $this->getHoldingsSummary($data, $id);
             $data[] = $summary;
         }
         return $data;
@@ -1078,13 +1078,14 @@ public function getPickUpLocations($patron = false, $holdDetails = null)
     /**
      * Return summary of holdings items.
      *
-     * @param array $holdings Parsed holdings items
+     * @param array  $holdings Parsed holdings items
+     * @param string $id       Record id
      *
      * @return array summary
      */
-    protected function getHoldingsSummary($holdings)
+    protected function getHoldingsSummary($holdings, $id)
     {
-        $availableTotal = $itemsTotal = $reservationsTotal = 0;
+        $availableTotal = $itemsTotal = 0;
         $requests = 0;
         $locations = [];
 
@@ -1108,12 +1109,13 @@ protected function getHoldingsSummary($holdings)
         // Use a stupid location name to make sure this doesn't get mixed with
         // real items that don't have a proper location.
         $result = [
-           'available' => $availableTotal,
-           'total' => $itemsTotal,
-           'locations' => count($locations),
-           'availability' => null,
-           'callnumber' => null,
-           'location' => '__HOLDINGSSUMMARYLOCATION__',
+            'id' => $id,
+            'available' => $availableTotal,
+            'total' => $itemsTotal,
+            'locations' => count($locations),
+            'availability' => null,
+            'callnumber' => '',
+            'location' => '__HOLDINGSSUMMARYLOCATION__',
         ];
         if (!empty($this->config['Holdings']['display_total_hold_count'])) {
             $result['reservations'] = $requests;
diff --git a/module/Finna/src/Finna/ILS/Driver/Mikromarc.php b/module/Finna/src/Finna/ILS/Driver/Mikromarc.php
index 8ac235dfa2f..270cf501a1c 100644
--- a/module/Finna/src/Finna/ILS/Driver/Mikromarc.php
+++ b/module/Finna/src/Finna/ILS/Driver/Mikromarc.php
@@ -257,7 +257,7 @@ public function getHolding($id, array $patron = null, array $options = [])
     {
         $data = $this->getItemStatusesForBiblio($id, $patron);
         if (!empty($data)) {
-            $summary = $this->getHoldingsSummary($data);
+            $summary = $this->getHoldingsSummary($data, $id);
             $data[] = $summary;
         }
         return $data;
@@ -1769,11 +1769,12 @@ protected function getItemStatusesForBiblio($id, $patron = null)
     /**
      * Return summary of holdings items.
      *
-     * @param array $holdings Parsed holdings items
+     * @param array  $holdings Parsed holdings items
+     * @param string $id       Record id
      *
      * @return array summary
      */
-    protected function getHoldingsSummary($holdings)
+    protected function getHoldingsSummary($holdings, $id)
     {
         $holdable = false;
         $titleHold = true;
@@ -1803,17 +1804,18 @@ protected function getHoldingsSummary($holdings)
         // we need to add a few dummy-fields that VuFind expects to be
         // defined for all elements.
         return [
-           'available' => $availableTotal,
-           'ordered' => $orderedTotal,
-           'total' => $itemsTotal,
-           'reservations' => $reservationsTotal,
-           'locations' => count($locations),
-           'holdable' => $holdable,
-           'availability' => null,
-           'callnumber' => null,
-           'location' => '__HOLDINGSSUMMARYLOCATION__',
-           'groupBranches' => false,
-           'titleHold' => $titleHold,
+            'id' => $id,
+            'available' => $availableTotal,
+            'ordered' => $orderedTotal,
+            'total' => $itemsTotal,
+            'reservations' => $reservationsTotal,
+            'locations' => count($locations),
+            'holdable' => $holdable,
+            'availability' => null,
+            'callnumber' => '',
+            'location' => '__HOLDINGSSUMMARYLOCATION__',
+            'groupBranches' => false,
+            'titleHold' => $titleHold,
         ];
     }
 
diff --git a/module/Finna/src/Finna/ILS/Driver/SierraRest.php b/module/Finna/src/Finna/ILS/Driver/SierraRest.php
index e21d9f79c7f..ecee314be13 100644
--- a/module/Finna/src/Finna/ILS/Driver/SierraRest.php
+++ b/module/Finna/src/Finna/ILS/Driver/SierraRest.php
@@ -1255,12 +1255,13 @@ protected function getItemStatusesForBib(string $id, bool $checkHoldings, ?array
             // we need to add a few dummy-fields that VuFind expects to be
             // defined for all elements.
             $summary = [
+                'id' => $id,
                 'available' => $itemsAvailable,
                 'total' => $itemsTotal,
                 'ordered' => $itemsOrdered,
                 'locations' => count(array_unique(array_column($statuses, 'location'))),
                 'availability' => null,
-                'callnumber' => null,
+                'callnumber' => '',
                 'location' => '__HOLDINGSSUMMARYLOCATION__',
             ];
             if ($this->config['Holdings']['display_total_hold_count'] ?? true) {