diff --git a/CRM/Import/Parser.php b/CRM/Import/Parser.php
index 5574ce39f92a..0c867dc80440 100644
--- a/CRM/Import/Parser.php
+++ b/CRM/Import/Parser.php
@@ -1518,81 +1518,6 @@ protected function getContactMatchingFields(): array {
     return $fields;
   }
 
-  /**
-   * @param $customFieldID
-   * @param $value
-   * @param array $fieldMetaData
-   * @param $dateType
-   *
-   * @return ?string
-   */
-  protected function validateCustomField($customFieldID, $value, array $fieldMetaData, $dateType): ?string {
-    /* validate the data against the CF type */
-
-    if ($value) {
-      $dataType = $fieldMetaData['data_type'];
-      $htmlType = $fieldMetaData['html_type'];
-      $isSerialized = CRM_Core_BAO_CustomField::isSerialized($fieldMetaData);
-      if ($dataType === 'Date') {
-        $params = ['date_field' => $value];
-        if (CRM_Utils_Date::convertToDefaultDate($params, $dateType, 'date_field')) {
-          return NULL;
-        }
-        return $fieldMetaData['label'];
-      }
-      elseif ($dataType === 'Boolean') {
-        if (CRM_Utils_String::strtoboolstr($value) === FALSE) {
-          return $fieldMetaData['label'] . '::' . $fieldMetaData['groupTitle'];
-        }
-      }
-      // need not check for label filed import
-      $selectHtmlTypes = [
-        'CheckBox',
-        'Select',
-        'Radio',
-      ];
-      if ((!$isSerialized && !in_array($htmlType, $selectHtmlTypes)) || $dataType == 'Boolean' || $dataType == 'ContactReference') {
-        $valid = CRM_Core_BAO_CustomValue::typecheck($dataType, $value);
-        if (!$valid) {
-          return $fieldMetaData['label'];
-        }
-      }
-
-      // check for values for custom fields for checkboxes and multiselect
-      if ($isSerialized && $dataType != 'ContactReference') {
-        $mulValues = array_filter(explode(',', str_replace('|', ',', trim($value))), 'strlen');
-        $customOption = CRM_Core_BAO_CustomOption::getCustomOption($customFieldID, TRUE);
-        foreach ($mulValues as $v1) {
-
-          $flag = FALSE;
-          foreach ($customOption as $v2) {
-            if ((strtolower(trim($v2['label'])) == strtolower(trim($v1))) || (strtolower(trim($v2['value'])) == strtolower(trim($v1)))) {
-              $flag = TRUE;
-            }
-          }
-
-          if (!$flag) {
-            return $fieldMetaData['label'];
-          }
-        }
-      }
-      elseif ($htmlType == 'Select' || ($htmlType == 'Radio' && $dataType != 'Boolean')) {
-        $customOption = CRM_Core_BAO_CustomOption::getCustomOption($customFieldID, TRUE);
-        $flag = FALSE;
-        foreach ($customOption as $v2) {
-          if ((strtolower(trim($v2['label'])) == strtolower(trim($value))) || (strtolower(trim($v2['value'])) == strtolower(trim($value)))) {
-            $flag = TRUE;
-          }
-        }
-        if (!$flag) {
-          return $fieldMetaData['label'];
-        }
-      }
-    }
-
-    return NULL;
-  }
-
   /**
    * Get the entity for the given field.
    *
@@ -1915,80 +1840,6 @@ public static function runJob(\CRM_Queue_TaskContext $taskContext, int $userJobI
     return TRUE;
   }
 
-  /**
-   * Check if an error in custom data.
-   *
-   * @deprecated all of this is duplicated if getTransformedValue is used.
-   *
-   * @param array $params
-   * @param string $errorMessage
-   *   A string containing all the error-fields.
-   *
-   * @param null $csType
-   */
-  public function isErrorInCustomData($params, &$errorMessage, $csType = NULL) {
-    $dateType = CRM_Core_Session::singleton()->get("dateTypes");
-    $errors = [];
-
-    if (!empty($params['contact_sub_type'])) {
-      $csType = $params['contact_sub_type'] ?? NULL;
-    }
-
-    if (empty($params['contact_type'])) {
-      $params['contact_type'] = 'Individual';
-    }
-
-    // get array of subtypes - CRM-18708
-    if (in_array($csType, CRM_Contact_BAO_ContactType::basicTypes(TRUE), TRUE)) {
-      $csType = $this->getSubtypes($params['contact_type']);
-    }
-
-    if (is_array($csType)) {
-      // fetch custom fields for every subtype and add it to $customFields array
-      // CRM-18708
-      $customFields = [];
-      foreach ($csType as $cType) {
-        $customFields += CRM_Core_BAO_CustomField::getFields($params['contact_type'], FALSE, FALSE, $cType);
-      }
-    }
-    else {
-      $customFields = CRM_Core_BAO_CustomField::getFields($params['contact_type'], FALSE, FALSE, $csType);
-    }
-
-    foreach ($params as $key => $value) {
-      if ($customFieldID = CRM_Core_BAO_CustomField::getKeyID($key)) {
-        //For address custom fields, we do get actual custom field value as an inner array of
-        //values so need to modify
-        if (!array_key_exists($customFieldID, $customFields)) {
-          return ts('field ID');
-        }
-        /* check if it's a valid custom field id */
-        $errors[] = $this->validateCustomField($customFieldID, $value, $customFields[$customFieldID], $dateType);
-      }
-    }
-    if ($errors) {
-      $errorMessage .= ($errorMessage ? '; ' : '') . implode('; ', array_filter($errors));
-    }
-  }
-
-  /**
-   * get subtypes given the contact type
-   *
-   * @param string $contactType
-   * @return array $subTypes
-   */
-  protected function getSubtypes($contactType) {
-    $subTypes = [];
-    $types = CRM_Contact_BAO_ContactType::subTypeInfo($contactType);
-
-    if (count($types) > 0) {
-      foreach ($types as $type) {
-        $subTypes[] = $type['name'];
-      }
-    }
-    return $subTypes;
-  }
-
   /**
    * Update the status of the import row to reflect the processing outcome.
    *
diff --git a/tests/phpunit/CRM/Contact/Import/Parser/ContactTest.php b/tests/phpunit/CRM/Contact/Import/Parser/ContactTest.php
index 17de9e8ebb63..2efd3dae0071 100644
--- a/tests/phpunit/CRM/Contact/Import/Parser/ContactTest.php
+++ b/tests/phpunit/CRM/Contact/Import/Parser/ContactTest.php
@@ -973,24 +973,6 @@ public function testImportPrimaryAddressUpdate(): void {
     $this->callAPISuccessGetSingle('Contact', $contactValues);
   }
 
-  /**
-   * Test the determination of whether a custom field is valid.
-   */
-  public function testCustomFieldValidation(): void {
-    $errorMessage = '';
-    $customGroup = $this->customGroupCreate([
-      'extends' => 'Contact',
-      'title' => 'ABC',
-    ]);
-    $customField = $this->customFieldOptionValueCreate($customGroup, 'fieldABC', ['html_type' => 'Select', 'serialize' => 1]);
-    $params = [
-      'custom_' . $customField['id'] => 'Label1|Label2',
-    ];
-    $parser = new CRM_Contact_Import_Parser_Contact();
-    $parser->isErrorInCustomData($params, $errorMessage);
-    $this->assertEquals(NULL, $errorMessage);
-  }
-
   /**
    * Test the import validation.
    *