diff --git a/CRM/Activity/Form/Task.php b/CRM/Activity/Form/Task.php
index 23afcfab94b2..ee6e1ebd2b8a 100644
--- a/CRM/Activity/Form/Task.php
+++ b/CRM/Activity/Form/Task.php
@@ -127,4 +127,13 @@ public function addDefaultButtons($title, $nextType = 'next', $backType = 'back'
     ]);
   }
 
+  /**
+   * Get the token processor schema required to list any tokens for this task.
+   *
+   * @return array
+   */
+  public function getTokenSchema(): array {
+    return ['activityId'];
+  }
+
 }
diff --git a/CRM/Activity/Form/Task/PDF.php b/CRM/Activity/Form/Task/PDF.php
index 760bde39eadc..8a7cd7abb0dd 100644
--- a/CRM/Activity/Form/Task/PDF.php
+++ b/CRM/Activity/Form/Task/PDF.php
@@ -56,15 +56,6 @@ public function postProcess() {
     CRM_Utils_System::civiExit(0);
   }
 
-  /**
-   * List available tokens for this form.
-   *
-   * @return array
-   */
-  public function listTokens() {
-    return $this->createTokenProcessor()->listTokens();
-  }
-
   /**
    * Create a token processor
    *
diff --git a/CRM/Case/Form/Task.php b/CRM/Case/Form/Task.php
index d1f318ac4322..0734653c2f3b 100644
--- a/CRM/Case/Form/Task.php
+++ b/CRM/Case/Form/Task.php
@@ -68,6 +68,23 @@ public function orderBy() {
     return 'ORDER BY ' . implode(',', $order_array);
   }
 
+  /**
+   * Get the rows from the results to be pdf-d.
+   *
+   * @return array
+   */
+  protected function getRows(): array {
+    $rows = [];
+    foreach ($this->_contactIds as $index => $contactID) {
+      $caseID = $this->getVar('_caseId');
+      if (empty($caseID) && !empty($this->_caseIds[$index])) {
+        $caseID = $this->_caseIds[$index];
+      }
+      $rows[] = ['contactId' => $contactID, 'caseId' => $caseID];
+    }
+    return $rows;
+  }
+
   /**
    * Get the name of the table for the relevant entity.
    *
diff --git a/CRM/Contact/Form/Task.php b/CRM/Contact/Form/Task.php
index 67b7f2be125f..2a2ad62c635d 100644
--- a/CRM/Contact/Form/Task.php
+++ b/CRM/Contact/Form/Task.php
@@ -137,7 +137,7 @@ public static function preProcessCommon(&$form) {
       // since we don't store all contacts in prevnextcache, when user selects "all" use query to retrieve contacts
       // rather than prevnext cache table for most of the task actions except export where we rebuild query to fetch
       // final result set
-      $allCids[$cacheKey] = self::getContactIds($form);
+      $allCids[$cacheKey] = self::legacyGetContactIds($form);
 
       $form->_contactIds = [];
       if (empty($form->_contactIds)) {
@@ -222,11 +222,16 @@ public static function preProcessCommon(&$form) {
    *   - custom search (FIXME: does this still apply to custom search?).
    * When we call this function we are not using the prev/next cache
    *
+   * We've started to try to move away from these functions
+   * being static. Probably we need to convert the export forms
+   * to use a trait based approach. For now this is renamed to
+   * permit the use of a non-static function with this name
+   *
    * @param $form CRM_Core_Form
    *
    * @return array $contactIds
    */
-  public static function getContactIds($form) {
+  protected static function legacyGetContactIds($form) {
     // need to perform action on all contacts
     // fire the query again and get the contact id's + display name
     $sortID = NULL;
diff --git a/CRM/Contact/Form/Task/PDF.php b/CRM/Contact/Form/Task/PDF.php
index 9688e912e3e6..66f1138eb594 100644
--- a/CRM/Contact/Form/Task/PDF.php
+++ b/CRM/Contact/Form/Task/PDF.php
@@ -110,4 +110,26 @@ public function listTokens() {
     return $tokens;
   }
 
+  /**
+   * Get the rows from the results to be pdf-d.
+   *
+   * @todo the case handling should be in the case pdf task.
+   * It needs fixing to support standalone & some url fixes
+   *
+   * similar to https://github.com/civicrm/civicrm-core/pull/21688
+   *
+   * @return array
+   */
+  protected function getRows(): array {
+    $rows = [];
+    foreach ($this->_contactIds as $index => $contactID) {
+      $caseID = $this->getVar('_caseId');
+      if (empty($caseID) && !empty($this->_caseIds[$index])) {
+        $caseID = $this->_caseIds[$index];
+      }
+      $rows[] = ['contactId' => $contactID, 'caseId' => $caseID];
+    }
+    return $rows;
+  }
+
 }
diff --git a/CRM/Contact/Form/Task/PDFTrait.php b/CRM/Contact/Form/Task/PDFTrait.php
index e0877493ce37..2cfa43c87bb8 100644
--- a/CRM/Contact/Form/Task/PDFTrait.php
+++ b/CRM/Contact/Form/Task/PDFTrait.php
@@ -237,16 +237,11 @@ public function postProcess(): void {
       [$html_message, $zip] = CRM_Utils_PDF_Document::unzipDoc($formValues['document_file_path'], $formValues['document_type']);
     }
 
-    foreach ($this->_contactIds as $item => $contactId) {
-      $caseId = $this->getVar('_caseId');
-      if (empty($caseId) && !empty($this->_caseIds[$item])) {
-        $caseId = $this->_caseIds[$item];
-      }
-
+    foreach ($this->getRows() as $row) {
       $tokenHtml = CRM_Core_BAO_MessageTemplate::renderTemplate([
-        'contactId' => $contactId,
+        'contactId' => $row['contactId'],
         'messageTemplate' => ['msg_html' => $html_message],
-        'tokenContext' => $caseId ? ['caseId' => $caseId] : [],
+        'tokenContext' => array_merge($row, ['schema' => $this->getTokenSchema()]),
         'disableSmarty' => (!defined('CIVICRM_MAIL_SMARTY') || !CIVICRM_MAIL_SMARTY),
       ])['html'];
 
diff --git a/CRM/Contribute/Form/Task.php b/CRM/Contribute/Form/Task.php
index b15aa0e23894..9a3b30871fe3 100644
--- a/CRM/Contribute/Form/Task.php
+++ b/CRM/Contribute/Form/Task.php
@@ -104,4 +104,13 @@ public function addDefaultButtons($title, $nextType = 'next', $backType = 'back'
     ]);
   }
 
+  /**
+   * Get the token processor schema required to list any tokens for this task.
+   *
+   * @return array
+   */
+  public function getTokenSchema(): array {
+    return ['contributionId', 'contactId'];
+  }
+
 }
diff --git a/CRM/Contribute/Form/Task/Email.php b/CRM/Contribute/Form/Task/Email.php
index db83653ea539..7fb87e4c97f7 100644
--- a/CRM/Contribute/Form/Task/Email.php
+++ b/CRM/Contribute/Form/Task/Email.php
@@ -32,15 +32,4 @@ protected function getContributionIDs(): array {
     return $this->getIDs();
   }
 
-  /**
-   * List available tokens for this form.
-   *
-   * @return array
-   */
-  public function listTokens() {
-    $tokens = CRM_Core_SelectValues::contactTokens();
-    $tokens = array_merge(CRM_Core_SelectValues::contributionTokens(), $tokens);
-    return $tokens;
-  }
-
 }
diff --git a/CRM/Contribute/Form/Task/PDFLetter.php b/CRM/Contribute/Form/Task/PDFLetter.php
index ce5839b7123a..e6b639f09e7c 100644
--- a/CRM/Contribute/Form/Task/PDFLetter.php
+++ b/CRM/Contribute/Form/Task/PDFLetter.php
@@ -293,15 +293,12 @@ protected function isSendEmails(): bool {
   }
 
   /**
-   * List available tokens for this form.
+   * Get the token processor schema required to list any tokens for this task.
    *
    * @return array
    */
-  public function listTokens() {
-    $tokens = CRM_Core_SelectValues::contactTokens();
-    $tokens = array_merge(CRM_Core_SelectValues::contributionTokens(), $tokens);
-    $tokens = array_merge(CRM_Core_SelectValues::domainTokens(), $tokens);
-    return $tokens;
+  public function getTokenSchema(): array {
+    return ['contributionId', 'contactId'];
   }
 
   /**
diff --git a/CRM/Core/Form/Task.php b/CRM/Core/Form/Task.php
index cb4c7349c9da..81ed62d15caf 100644
--- a/CRM/Core/Form/Task.php
+++ b/CRM/Core/Form/Task.php
@@ -9,6 +9,8 @@
  +--------------------------------------------------------------------+
  */
 
+use Civi\Token\TokenProcessor;
+
 /**
  * @package CRM
  * @copyright CiviCRM LLC https://civicrm.org/licensing
@@ -338,4 +340,45 @@ public function getEntityAliasField() {
     return $this::$entityShortname . '_id';
   }
 
+  /**
+   * List available tokens for this form.
+   *
+   * @return array
+   */
+  public function listTokens() {
+    $tokenProcessor = new TokenProcessor(Civi::dispatcher(), ['schema' => $this->getTokenSchema()]);
+    return $tokenProcessor->listTokens();
+  }
+
+  /**
+   * Get the token processor schema required to list any tokens for this task.
+   *
+   * @return array
+   */
+  protected function getTokenSchema(): array {
+    return ['contactId'];
+  }
+
+  /**
+   * Get the rows from the results.
+   *
+   * @return array
+   */
+  protected function getRows(): array {
+    $rows = [];
+    foreach ($this->getContactIDs() as $contactID) {
+      $rows[] = ['contactId' => $contactID];
+    }
+    return $rows;
+  }
+
+  /**
+   * Get the relevant contact IDs.
+   *
+   * @return array
+   */
+  protected function getContactIDs(): array {
+    return $this->_contactIds ?? [];
+  }
+
 }
diff --git a/CRM/Event/Form/Task.php b/CRM/Event/Form/Task.php
index e3bbae330dac..20704e0e9392 100644
--- a/CRM/Event/Form/Task.php
+++ b/CRM/Event/Form/Task.php
@@ -15,6 +15,8 @@
  * @copyright CiviCRM LLC https://civicrm.org/licensing
  */
 
+use Civi\Api4\Participant;
+
 /**
  * Class for event form task actions.
  * FIXME: This needs refactoring to properly inherit from CRM_Core_Form_Task and share more functions.
@@ -28,6 +30,16 @@ class CRM_Event_Form_Task extends CRM_Core_Form_Task {
    */
   protected $_participantIds;
 
+  /**
+   * Rows to act on.
+   *
+   * Each row will have a participant ID & a contact ID using
+   * the keys the token processor expects.
+   *
+   * @var array
+   */
+  protected $rows = [];
+
   /**
    * Build all the data structures needed to build the form.
    *
@@ -83,14 +95,36 @@ public static function preProcessCommon(&$form) {
     $form->setNextUrl('event');
   }
 
+  /**
+   * Get the participant IDs.
+   *
+   * @return array
+   */
+  public function getIDs(): array {
+    return $this->_participantIds;
+  }
+
   /**
    * Given the participant id, compute the contact id
    * since its used for things like send email
    */
-  public function setContactIDs() {
-    $this->_contactIds = CRM_Core_DAO::getContactIDsFromComponent($this->_participantIds,
-      'civicrm_participant'
-    );
+  public function setContactIDs(): void {
+    $this->_contactIds = $this->getContactIDs();
+  }
+
+  /**
+   * Get the relevant contact IDs.
+   *
+   * @return array
+   */
+  protected function getContactIDs(): array {
+    if (isset($this->_contactIds)) {
+      return $this->_contactIds;
+    }
+    foreach ($this->getRows() as $row) {
+      $this->_contactIds[] = $row['contactId'];
+    }
+    return $this->_contactIds;
   }
 
   /**
@@ -119,4 +153,35 @@ public function addDefaultButtons($title, $nextType = 'next', $backType = 'back'
     ]);
   }
 
+  /**
+   * Get the rows form the search, keyed to make the token processor happy.
+   *
+   * @throws \API_Exception
+   */
+  public function getRows(): array {
+    if (empty($this->rows)) {
+      // checkPermissions set to false - in case form is bypassing in some way.
+      $participants = Participant::get(FALSE)
+        ->addWhere('id', 'IN', $this->getIDs())
+        ->setSelect(['id', 'contact_id'])->execute();
+      foreach ($participants as $participant) {
+        $this->rows[] = [
+          // We map to this funky format for the token processor :-(
+          'contactId' => $participant['contact_id'],
+          'participantId' => $participant['id'],
+        ];
+      }
+    }
+    return $this->rows;
+  }
+
+  /**
+   * Get the token processor schema required to list any tokens for this task.
+   *
+   * @return array
+   */
+  public function getTokenSchema(): array {
+    return ['participantId', 'contactId', 'eventId'];
+  }
+
 }
diff --git a/CRM/Event/Form/Task/PDF.php b/CRM/Event/Form/Task/PDF.php
index 778a195f2bab..0f0d25436f4f 100644
--- a/CRM/Event/Form/Task/PDF.php
+++ b/CRM/Event/Form/Task/PDF.php
@@ -48,21 +48,7 @@ class CRM_Event_Form_Task_PDF extends CRM_Event_Form_Task {
   public function preProcess() {
     $this->preProcessPDF();
     parent::preProcess();
-
-    // we have all the participant ids, so now we get the contact ids
-    parent::setContactIDs();
-
     $this->assign('single', $this->_single);
   }
 
-  /**
-   * List available tokens for this form.
-   *
-   * @return array
-   */
-  public function listTokens() {
-    $tokens = CRM_Core_SelectValues::contactTokens();
-    return $tokens;
-  }
-
 }
diff --git a/CRM/Event/ParticipantTokens.php b/CRM/Event/ParticipantTokens.php
index 5733e10af9e2..f33af5d2b545 100644
--- a/CRM/Event/ParticipantTokens.php
+++ b/CRM/Event/ParticipantTokens.php
@@ -10,6 +10,7 @@
  +--------------------------------------------------------------------+
  */
 
+use Civi\Token\Event\TokenValueEvent;
 use Civi\Token\TokenRow;
 
 /**
@@ -42,6 +43,21 @@ public function getCurrencyFieldName(): array {
     return ['fee_currency'];
   }
 
+  /**
+   * To handle variable tokens, override this function and return the active tokens.
+   *
+   * @param \Civi\Token\Event\TokenValueEvent $e
+   *
+   * @return mixed
+   */
+  public function getActiveTokens(TokenValueEvent $e) {
+    $messageTokens = $e->getTokenProcessor()->getMessageTokens();
+    if (!isset($messageTokens[$this->entity])) {
+      return isset($messageTokens['event']) ? ['event_id'] : FALSE;
+    }
+    return parent::getActiveTokens($e);
+  }
+
   /**
    * Get any tokens with custom calculation.
    */
diff --git a/CRM/Member/Form/Task.php b/CRM/Member/Form/Task.php
index 8d5d042ab8b2..9dd37aa1b90f 100644
--- a/CRM/Member/Form/Task.php
+++ b/CRM/Member/Form/Task.php
@@ -95,4 +95,13 @@ public function setContactIDs() {
     );
   }
 
+  /**
+   * Get the token processor schema required to list any tokens for this task.
+   *
+   * @return array
+   */
+  public function getTokenSchema(): array {
+    return ['membershipId', 'contactId'];
+  }
+
 }
diff --git a/CRM/Member/Form/Task/PDFLetter.php b/CRM/Member/Form/Task/PDFLetter.php
index 1d2354e3b4b1..f7464b1b705f 100644
--- a/CRM/Member/Form/Task/PDFLetter.php
+++ b/CRM/Member/Form/Task/PDFLetter.php
@@ -138,14 +138,12 @@ public function generateHTML($membershipIDs, $messageToken, $html_message): arra
   }
 
   /**
-   * List available tokens for this form.
+   * Get the token processor schema required to list any tokens for this task.
    *
    * @return array
    */
-  public function listTokens() {
-    $tokens = CRM_Core_SelectValues::contactTokens();
-    $tokens = array_merge(CRM_Core_SelectValues::membershipTokens(), $tokens);
-    return $tokens;
+  public function getTokenSchema(): array {
+    return ['membershipId', 'contactId'];
   }
 
 }
diff --git a/Civi/Token/TokenRow.php b/Civi/Token/TokenRow.php
index 96ea17816656..680e7c0e3693 100644
--- a/Civi/Token/TokenRow.php
+++ b/Civi/Token/TokenRow.php
@@ -174,8 +174,8 @@ public function tokens($a = NULL, $b = NULL, $c = NULL) {
    * @return TokenRow
    */
   public function customToken($entity, $customFieldID, $entityID) {
-    $customFieldName = "custom_" . $customFieldID;
-    $record = civicrm_api3($entity, "getSingle", [
+    $customFieldName = 'custom_' . $customFieldID;
+    $record = civicrm_api3($entity, 'getSingle', [
       'return' => $customFieldName,
       'id' => $entityID,
     ]);
@@ -183,7 +183,7 @@ public function customToken($entity, $customFieldID, $entityID) {
 
     // format the raw custom field value into proper display value
     if (isset($fieldValue)) {
-      $fieldValue = \CRM_Core_BAO_CustomField::displayValue($fieldValue, $customFieldID);
+      $fieldValue = (string) \CRM_Core_BAO_CustomField::displayValue($fieldValue, $customFieldID);
     }
 
     return $this->format('text/html')->tokens($entity, $customFieldName, $fieldValue);
diff --git a/tests/phpunit/CRM/Utils/TokenConsistencyTest.php b/tests/phpunit/CRM/Utils/TokenConsistencyTest.php
index 92f1048c25fa..33612e5778dd 100644
--- a/tests/phpunit/CRM/Utils/TokenConsistencyTest.php
+++ b/tests/phpunit/CRM/Utils/TokenConsistencyTest.php
@@ -569,6 +569,24 @@ public function testParticipantTokenConsistency(): void {
 
   }
 
+  /**
+   * Test that membership tokens are consistently rendered.
+   *
+   * @throws \API_Exception
+   * @throws \CRM_Core_Exception
+   */
+  public function testParticipantCustomDateToken(): void {
+    $this->createEventAndParticipant();
+    $dateFieldID = $this->createDateCustomField(['custom_group_id' => $this->ids['CustomGroup']['participant_'], 'default_value' => ''])['id'];
+    $input = '{participant.custom_' . $dateFieldID . '}';
+    $input .= '{participant.' . $this->getCustomFieldName('participant_int') . '}';
+    $tokenHtml = CRM_Core_BAO_MessageTemplate::renderTemplate([
+      'messageTemplate' => ['msg_html' => $input],
+      'tokenContext' => array_merge(['participantId' => $this->ids['participant'][0]], ['schema' => ['participantId', 'eventId']]),
+    ])['html'];
+    $this->assertEquals(99999, $tokenHtml);
+  }
+
   /**
    * Get declared participant tokens.
    *
@@ -745,45 +763,12 @@ public function testEventTokenConsistencyNoParticipantTokens(): void {
    * @throws \API_Exception
    */
   public function setupParticipantScheduledReminder($includeParticipant = TRUE): void {
-    $this->createCustomGroupWithFieldOfType(['extends' => 'Event']);
-    $this->createCustomGroupWithFieldOfType(['extends' => 'Participant'], 'int', 'participant_');
-    $html = '';
+    $this->createEventAndParticipant();
     $tokens = array_keys($this->getEventTokens());
     if ($includeParticipant) {
       $tokens = array_keys(array_merge($this->getEventTokens(), $this->getParticipantTokens()));
     }
     $html = $this->getTokenString($tokens);
-    $emailID = Email::create()->setValues(['email' => 'event@example.com'])->execute()->first()['id'];
-    $addressID = Address::create()->setValues([
-      'street_address' => '15 Walton St',
-      'supplemental_address_1' => 'up the road',
-      'city' => 'Emerald City',
-      'state_province_id:label' => 'Maine',
-      'postal_code' => 90210,
-    ])->execute()->first()['id'];
-    $phoneID = Phone::create()->setValues(['phone' => '456 789'])->execute()->first()['id'];
-
-    $locationBlockID = LocBlock::save(FALSE)->setRecords([
-      [
-        'email_id' => $emailID,
-        'address_id' => $addressID,
-        'phone_id' => $phoneID,
-      ],
-    ])->execute()->first()['id'];
-    $this->ids['event'][0] = $this->eventCreate([
-      'description' => 'event description',
-      $this->getCustomFieldName('text') => 'my field',
-      'loc_block_id' => $locationBlockID,
-    ])['id'];
-    // Create an unrelated participant record so that the ids don't match.
-    // this prevents things working just because the id 'happens to be valid'
-    $this->participantCreate(['register_date' => '2020-01-01', 'event_id' => $this->ids['event'][0]]);
-    $this->ids['participant'][0] = $this->participantCreate([
-      'event_id' => $this->ids['event'][0],
-      'fee_amount' => 50,
-      'fee_level' => 'steep',
-      $this->getCustomFieldName('participant_int') => '99999',
-    ]);
     CRM_Utils_Time::setTime('2007-02-20 15:00:00');
     $this->callAPISuccess('action_schedule', 'create', [
       'title' => 'job',
@@ -834,4 +819,54 @@ protected function getTokenString(array $tokens): string {
     return $html;
   }
 
+  /**
+   * Create an event with a participant.
+   *
+   * @throws \API_Exception
+   */
+  protected function createEventAndParticipant(): void {
+    $this->createCustomGroupWithFieldOfType(['extends' => 'Event']);
+    $this->createCustomGroupWithFieldOfType(['extends' => 'Participant'], 'int', 'participant_');
+    $emailID = Email::create()
+      ->setValues(['email' => 'event@example.com'])
+      ->execute()
+      ->first()['id'];
+    $addressID = Address::create()->setValues([
+      'street_address' => '15 Walton St',
+      'supplemental_address_1' => 'up the road',
+      'city' => 'Emerald City',
+      'state_province_id:label' => 'Maine',
+      'postal_code' => 90210,
+    ])->execute()->first()['id'];
+    $phoneID = Phone::create()
+      ->setValues(['phone' => '456 789'])
+      ->execute()
+      ->first()['id'];
+
+    $locationBlockID = LocBlock::save(FALSE)->setRecords([
+      [
+        'email_id' => $emailID,
+        'address_id' => $addressID,
+        'phone_id' => $phoneID,
+      ],
+    ])->execute()->first()['id'];
+    $this->ids['event'][0] = $this->eventCreate([
+      'description' => 'event description',
+      $this->getCustomFieldName('text') => 'my field',
+      'loc_block_id' => $locationBlockID,
+    ])['id'];
+    // Create an unrelated participant record so that the ids don't match.
+    // this prevents things working just because the id 'happens to be valid'
+    $this->participantCreate([
+      'register_date' => '2020-01-01',
+      'event_id' => $this->ids['event'][0],
+    ]);
+    $this->ids['participant'][0] = $this->participantCreate([
+      'event_id' => $this->ids['event'][0],
+      'fee_amount' => 50,
+      'fee_level' => 'steep',
+      $this->getCustomFieldName('participant_int') => '99999',
+    ]);
+  }
+
 }