diff --git a/src/Component/Helper/FillPdfMappingHelper.php b/src/Component/Helper/FillPdfMappingHelper.php
index d1fd27474cfebb270f40355a02f5c192e5ebd898..59028cd868047bc62408db981755a1c0a59b7975 100644
--- a/src/Component/Helper/FillPdfMappingHelper.php
+++ b/src/Component/Helper/FillPdfMappingHelper.php
@@ -43,28 +43,4 @@ class FillPdfMappingHelper implements FillPdfMappingHelperInterface {
     }
   }
 
-  /**
-   * Applies form and field level replacements to a string.
-   *
-   * @param string $value
-   *   The value to replace. Must match the key in a replacements field exactly.
-   * @param array $form_replacements
-   *   A list of form-level replacements.
-   * @param array $field_replacements
-   *   A list of field-level replacements. These have precedence.
-   *
-   * @return string
-   *   $value with any matching replacements applied.
-   *
-   * @deprecated in fillpdf:8.x-4.7 and is removed from fillpdf:8.x-5.0.
-   * Deprecated in core.
-   * @see https://www.drupal.org/project/fillpdf/issues/3044743
-   */
-  public static function transformString($value, array $form_replacements, array $field_replacements) {
-    @trigger_error('transformString is deprecated in fillpdf:8.x-4.7 and is removed from fillpdf:8.x-5.0. Deprecated in core. See https://www.drupal.org/project/fillpdf/issues/3044743', E_USER_DEPRECATED);
-    // Merge both with field-level replacements taking precedence.
-    $replacements = array_merge($form_replacements, $field_replacements);
-    return $replacements[$value] ?? $value;
-  }
-
 }
diff --git a/src/InputHelper.php b/src/InputHelper.php
index 7918654dd96b2d7bbe4517e48106abff19b17929..6b2701566af358a17d854b1be85e486726259225 100644
--- a/src/InputHelper.php
+++ b/src/InputHelper.php
@@ -123,21 +123,4 @@ class InputHelper implements InputHelperInterface {
     return $form_fields;
   }
 
-  /**
-   * Saves an uploaded file, marking it permanent.
-   *
-   * @param \Drupal\file\FileInterface $file
-   *   The file object to save.
-   *
-   * @deprecated in fillpdf:8.x-4.7 and is removed from fillpdf:8.x-5.0.
-   *   Use FileInterface::setPermanent() and FileInterface::save() instead.
-   * @see https://www.drupal.org/project/fillpdf/issues/3055123
-   * @see \Drupal\file\FileInterface
-   */
-  protected function saveFileUpload(FileInterface $file) {
-    @trigger_error('InputHelper::saveFileUpload() is deprecated in fillpdf:8.x-4.7 and is removed from fillpdf:8.x-5.0. Use \Drupal\file\FileInterface::setPermanent() and \Drupal\file\FileInterface::save() instead. See https://www.drupal.org/project/fillpdf/issues/3055123', E_USER_DEPRECATED);
-    $file->setPermanent();
-    $file->save();
-  }
-
 }
diff --git a/src/Plugin/FillPdfActionPluginBase.php b/src/Plugin/FillPdfActionPluginBase.php
index 18ee104e2a09d5d391672fbab2431ce5a867570f..cf3d56097c256dcf974be8edc7197b3528a4bf34 100644
--- a/src/Plugin/FillPdfActionPluginBase.php
+++ b/src/Plugin/FillPdfActionPluginBase.php
@@ -24,66 +24,4 @@ abstract class FillPdfActionPluginBase extends PluginBase implements FillPdfActi
     return [];
   }
 
-  /**
-   * Gets this plugin's configuration.
-   *
-   * @return array
-   *   An array of this plugin's configuration.
-   *
-   * @todo Remove superfluous docs once drupal:8.6.x is no longer supported.
-   * @deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom
-   *   FillPdfActionPlugins may implement ConfigurableInterface instead.
-   * @see https://www.drupal.org/project/fillpdf/issues/3058862
-   * @see \Drupal\Component\Plugin\ConfigurableInterface::getConfiguration()
-   */
-  public function getConfiguration() {
-    @trigger_error('FillPdfActionPluginInterface::getConfiguration() is deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom FillPdfActionPlugins may extend ConfigurableInterface instead. See https://www.drupal.org/project/fillpdf/issues/3058862', E_USER_DEPRECATED);
-    return $this->configuration;
-  }
-
-  /**
-   * Sets the configuration for this plugin instance.
-   *
-   * @param array $configuration
-   *   An associative array containing the plugin's configuration.
-   *
-   * @todo Remove superfluous docs once drupal:8.6.x is no longer supported.
-   * @deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom
-   *   FillPdfActionPlugins may implement ConfigurableInterface instead.
-   * @see https://www.drupal.org/project/fillpdf/issues/3058862
-   * @see \Drupal\Component\Plugin\ConfigurableInterface::setConfiguration()
-   */
-  public function setConfiguration(array $configuration) {
-    @trigger_error('FillPdfActionPluginInterface::setConfiguration() is deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom FillPdfActionPlugins may extend ConfigurableInterface instead. See https://www.drupal.org/project/fillpdf/issues/3058862', E_USER_DEPRECATED);
-    $this->configuration = $configuration;
-  }
-
-  /**
-   * Gets default configuration for this plugin.
-   *
-   * @return array
-   *   An associative array with the default configuration.
-   *
-   * @todo Remove superfluous docs once drupal:8.6.x is no longer supported.
-   * @deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom
-   *   FillPdfActionPlugins may implement ConfigurableInterface instead.
-   * @see https://www.drupal.org/project/fillpdf/issues/3058862
-   * @see \Drupal\Component\Plugin\ConfigurableInterface::defaultConfiguration()
-   */
-  public function defaultConfiguration() {
-    @trigger_error('FillPdfActionPluginInterface::defaultConfiguration() is deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom FillPdfActionPlugins may extend ConfigurableInterface instead. See https://www.drupal.org/project/fillpdf/issues/3058862', E_USER_DEPRECATED);
-    return [];
-  }
-
-  /**
-   * {@inheritdoc}
-   *
-   * @todo Remove once drupal:8.6.x is no longer supported.
-   * @see https://www.drupal.org/project/fillpdf/issues/3058862
-   */
-  public function isConfigurable() {
-    @trigger_error('FillPdfActionPluginBase::isConfigurable() is deprecated in fillpdf:8.x-4.8 and is removed from fillpdf:8.x-5.0. Custom FillPdfActionPlugins may extend ConfigurableInterface instead. See https://www.drupal.org/project/fillpdf/issues/3058862', E_USER_DEPRECATED);
-    return TRUE;
-  }
-
 }
diff --git a/src/Serializer.php b/src/Serializer.php
index 6538b7ab1a52a286b39a5b7b3add72af20aa4a38..23910772240b80792e9e8c82b108a3fe8254aabc 100644
--- a/src/Serializer.php
+++ b/src/Serializer.php
@@ -125,30 +125,4 @@ class Serializer implements SerializerInterface {
     return $unmatched_pdf_keys;
   }
 
-  /**
-   * Overwrites empty new field values with previous existing values.
-   *
-   * @param \Drupal\fillpdf\FillPdfFormFieldInterface[] $form_fields
-   *   Associative array of saved FillPdfFormField objects keyed by entity ID.
-   * @param string[] $existing_fields
-   *   (optional) Array of existing PDF keys.
-   *
-   * @return string[]
-   *   Array of unmatched PDF keys.
-   *
-   * @deprecated in fillpdf:8.x-4.7 and is removed from fillpdf:8.x-5.0.
-   *   Field lists are already keyed by pdf_key now, so rekeying them is
-   *   unnecessary. Use ::importFormFields instead.
-   * @see https://www.drupal.org/project/fillpdf/issues/3055097
-   * @see \Drupal\fillpdf\SerializerInterface::importFormFields()
-   */
-  public function importFormFieldsByKey(array $form_fields, array $existing_fields = []) {
-    @trigger_error('SerializerInterface::importFormFieldsByKey() is deprecated in fillpdf:8.x-4.7 and is removed from fillpdf:8.x-5.0. Use \Drupal\fillpdf\SerializerInterface::importFormFields() instead. See https://www.drupal.org/project/fillpdf/issues/3055097', E_USER_DEPRECATED);
-    $keyed_fields = [];
-    foreach ($form_fields as $form_field) {
-      $keyed_fields[$form_field->pdf_key->value] = $form_field;
-    }
-    return $this->importFormFields($keyed_fields, $existing_fields);
-  }
-
 }
diff --git a/src/Service/FillPdfAdminFormHelper.php b/src/Service/FillPdfAdminFormHelper.php
index 7859d03482a07072b8cd6200391bc80030bfb5fa..98c37ea23a95c06b7893fa6279f794c2a2264420 100644
--- a/src/Service/FillPdfAdminFormHelper.php
+++ b/src/Service/FillPdfAdminFormHelper.php
@@ -119,27 +119,4 @@ class FillPdfAdminFormHelper implements FillPdfAdminFormHelperInterface {
   with a blank, essentially erasing it.</p>");
   }
 
-  /**
-   * Returns the configured path to the local pdftk installation.
-   *
-   * @return string
-   *   The configured path to the local pdftk installation.
-   *
-   * @deprecated in fillpdf:8.x-4.9 and is removed from fillpdf:8.x-5.0. Use the
-   *   PdfBackend plugin's own methods.
-   *
-   * @see https://www.drupal.org/node/3060086
-   * @see \Drupal\fillpdf\Plugin\PdfBackend\PdftkPdfBackend
-   */
-  public function getPdftkPath() {
-    $path_to_pdftk = $this->configFactory->get('fillpdf.settings')
-      ->get('pdftk_path');
-
-    if (empty($path_to_pdftk)) {
-      $path_to_pdftk = 'pdftk';
-      return $path_to_pdftk;
-    }
-    return $path_to_pdftk;
-  }
-
 }