diff -u b/core/modules/user/src/Form/UserPasswordForm.php b/core/modules/user/src/Form/UserPasswordForm.php
--- b/core/modules/user/src/Form/UserPasswordForm.php
+++ b/core/modules/user/src/Form/UserPasswordForm.php
@@ -169,12 +169,8 @@
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $account = $form_state->getValue('account');
-
-    // $langcode will fallback to default langcode if property preferred_lancode is not set.
-    $langcode = $account->getPreferredLangcode();
-
     // Mail one time login URL and instructions using current language.
-    $mail = _user_mail_notify('password_reset', $account, $langcode);
+    $mail = _user_mail_notify('password_reset', $account);
     if (!empty($mail)) {
       $this->logger('user')->notice('Password reset instructions mailed to %name at %email.', ['%name' => $account->getAccountName(), '%email' => $account->getEmail()]);
       $this->messenger()->addStatus($this->t('Further instructions have been sent to your email address.'));
diff -u b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php
--- b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php
+++ b/core/modules/user/tests/src/Functional/UserPasswordResetTest.php
@@ -226,21 +226,7 @@
     $default_language_code = $this->languageManager->getDefaultLanguage()->getId();
 
     // Test password reset when language prefixes are not set.
-    $this->drupalGet('user/password');
-    $edit = ['name' => $this->account->getAccountName()];
-    $this->drupalPostForm(NULL, $edit, t('Submit'));
-    $this->assertValidPasswordReset($edit['name']);
-
-    $this->assertMailString('body', 'You may now log in by clicking this link or copying and pasting it into your browser:', 1);
-    $resetURL = $this->getResetURL();
-    $this->assertStringNotContainsString("$default_language_code/user/reset/", $resetURL);
-
-    // Ensure user can login with one-time login link.
-    $this->drupalGet($resetURL);
-    $this->drupalPostForm(NULL, [], t('Log in'));
-    $this->assertSession()->linkExists('Log out');
-    $this->assertSession()->titleEquals($this->account->getAccountName() . ' | Drupal');
-    $this->drupalLogout();
+    $this->assertLanguagePrefixResetUrl('user/password', '/user/reset', "$default_language_code/user/reset");
 
     // Set language prefixes.
     $config = $this->config('language.negotiation');
@@ -249,25 +235,15 @@
     $this->rebuildContainer();
 
     $this->drupalGet('zh/user/password');
-
-    // Test all language code set for browser, default.
-    $this->assertSame('zh-hant', $this->drupalGetHeader('Content-language'));
-    $this->assertSame('en', $this->languageManager->getDefaultLanguage()->getId());
-
-    // Test browser active language and default language is different.
-    $this->assertNotSame($this->languageManager->getDefaultLanguage()->getId(), $this->drupalGetHeader('Content-language'));
+    $this->assertLangcodeDifferent('zh-hant', 'en');
 
     // Set preferred language for user account.
     $this->account->preferred_langcode = 'fr';
     $this->account->save();
     $this->assertSame('fr', $this->account->getPreferredLangcode());
 
-    // Test reset URL respects preferred language over other lanugage settings.
-    $edit = ['name' => $this->account->getAccountName()];
-    $this->submitForm($edit, t('Submit'));
-    $this->assertMailString('body', '/fr/user/reset', 1);
-    $resetURL = $this->getResetURL();
-    $this->assertStringNotContainsString('/zh/user/reset', $resetURL);
+    // Test reset URL respects preferred language over other language settings.
+    $this->assertLanguagePrefixResetUrl('zh/user/password', '/fr/user/reset', '/zh/user/reset');
 
     // Unset preferred language for user account.
     $this->account->preferred_langcode = NULL;
@@ -276,16 +252,7 @@
 
     // Test reset URL respect default language over browser language when
     // preferred language is no set.
-    $this->drupalGet("zh/user/password");
-    $this->assertSame('zh-hant', $this->drupalGetHeader('Content-language'));
-    $this->assertSame('en', $this->languageManager->getDefaultLanguage()->getId());
-    $this->assertNotSame($this->languageManager->getDefaultLanguage()->getId(), $this->drupalGetHeader('Content-language'));
-
-    $edit = ['name' => $this->account->getAccountName()];
-    $this->submitForm($edit, t('Submit'));
-    $this->assertMailString('body', '/user/reset', 1);
-    $resetURL = $this->getResetURL();
-    $this->assertStringNotContainsString('/zh/user/reset', $resetURL);
+    $this->assertLanguagePrefixResetUrl('zh/user/password', '/user/reset', '/zh/user/reset');
 
     // Unset language prefixes.
     $config = $this->config('language.negotiation');
@@ -294,4 +261,40 @@
 
   /**
+   * Helper method for language prefix and reset url assertion.
+   *
+   * @param string $url
+   *   Url for drupalGet.
+   * @param string $expectContainString
+   *   String to expect from reset Url.
+   * @param string $expectNotContainString
+   *   String not to expect from reset Url.
+   */
+  public function assertLanguagePrefixResetUrl($url, $expectContainString, $expectNotContainString) {
+    $this->drupalGet($url);
+    $edit = ['name' => $this->account->getAccountName()];
+    $this->drupalPostForm(NULL, $edit, t('Submit'));
+    $this->assertValidPasswordReset($edit['name']);
+
+    $resetURL = $this->getResetURL();
+    $this->assertStringContainsString($expectContainString, $resetURL);
+    $this->assertStringNotContainsString($expectNotContainString, $resetURL);
+  }
+
+  /**
+   * Helper method to assert expected active language and
+   * default lanugage is different.
+   *
+   * @param string $activeLangcode
+   *   The active language code of your current session.
+   * @param string $defaultLangcode
+   *   The default language code of your site settings.
+   */
+  public function assertLangcodeDifferent($activeLangcode, $defaultLangcode) {
+    $this->assertSame($activeLangcode, $this->drupalGetHeader('Content-language'));
+    $this->assertSame($defaultLangcode, $this->languageManager->getDefaultLanguage()->getId());
+    $this->assertNotSame($this->languageManager->getDefaultLanguage()->getId(), $this->drupalGetHeader('Content-language'));
+  }
+
+  /**
    * Retrieves password reset email and extracts the login link.
    */