diff --git a/typo3/sysext/core/Documentation/Changelog/master/Breaking-78855-RemoveObsoleteSysActionTranslations.rst b/typo3/sysext/core/Documentation/Changelog/master/Breaking-78855-RemoveObsoleteSysActionTranslations.rst
new file mode 100644
index 0000000000000000000000000000000000000000..c0598929286edf20e43ddfbc923518c550ff8a34
--- /dev/null
+++ b/typo3/sysext/core/Documentation/Changelog/master/Breaking-78855-RemoveObsoleteSysActionTranslations.rst
@@ -0,0 +1,42 @@
+.. include:: ../../Includes.txt
+
+==========================================================
+Breaking: #78855 - Remove obsolete sys_action translations
+==========================================================
+
+See :issue:`78855`
+
+Description
+===========
+
+These translations are removed from `EXT:sys_action/Resources/Private/Language/locallang.xlf`:
+
+* action_BEu_hidden
+* action_BEu_username
+* action_BEu_password
+* action_BEu_realName
+* action_BEu_email
+* action_BEu_usergroups
+
+These translations are removed from `EXT:sys_action/Resources/Private/Language/locallang_tca.xlf`:
+
+* tx_sys_action
+
+Impact
+======
+
+Integrations / third party Extensions using these translations will break / output empty strings.
+
+
+Affected Installations
+======================
+
+Installations that use the removed translations in third party code.
+
+
+Migration
+=========
+
+Create your own `locallang.xlf` file and add the required translations.
+
+.. index:: Backend
diff --git a/typo3/sysext/sys_action/Resources/Private/Language/locallang.xlf b/typo3/sysext/sys_action/Resources/Private/Language/locallang.xlf
index 32b63cf635bda32a13d937d5715abe86c2ea7867..778506620f1ab9f6f7be1e971bb01c6acbe8f6d9 100644
--- a/typo3/sysext/sys_action/Resources/Private/Language/locallang.xlf
+++ b/typo3/sysext/sys_action/Resources/Private/Language/locallang.xlf
@@ -72,24 +72,6 @@
 			<trans-unit id="action_lowlevelMissing">
 				<source>The extension 'lowlevel' must be installed in order to create a query.</source>
 			</trans-unit>
-			<trans-unit id="action_BEu_hidden">
-				<source>Disable user</source>
-			</trans-unit>
-			<trans-unit id="action_BEu_username">
-				<source>Login name</source>
-			</trans-unit>
-			<trans-unit id="action_BEu_password">
-				<source>Password</source>
-			</trans-unit>
-			<trans-unit id="action_BEu_realName">
-				<source>Real name</source>
-			</trans-unit>
-			<trans-unit id="action_BEu_email">
-				<source>Email</source>
-			</trans-unit>
-			<trans-unit id="action_BEu_usergroups">
-				<source>Member of groups</source>
-			</trans-unit>
 			<trans-unit id="action_t2_result">
 				<source>Result of query</source>
 			</trans-unit>
@@ -108,12 +90,6 @@
 			<trans-unit id="action_t1_legend_configuration">
 				<source>Configuration</source>
 			</trans-unit>
-			<trans-unit id="action_BEu_db_mount">
-				<source>Pagetree starting points</source>
-			</trans-unit>
-			<trans-unit id="action_t4_edit">
-				<source>Select record to edit:</source>
-			</trans-unit>
 			<trans-unit id="action_toolbaritem">
 				<source>Open System Actions</source>
 			</trans-unit>
diff --git a/typo3/sysext/sys_action/Resources/Private/Language/locallang_tca.xlf b/typo3/sysext/sys_action/Resources/Private/Language/locallang_tca.xlf
index fb451bb4639f294dd0e9e8ebe80a878fe6a056af..e50fa155c1d63238ec57c954d1f0f68c9ca0dbd9 100644
--- a/typo3/sysext/sys_action/Resources/Private/Language/locallang_tca.xlf
+++ b/typo3/sysext/sys_action/Resources/Private/Language/locallang_tca.xlf
@@ -6,9 +6,6 @@
 			<trans-unit id="sys_action">
 				<source>Action</source>
 			</trans-unit>
-			<trans-unit id="tx_sys_action">
-				<source>Actions</source>
-			</trans-unit>
 			<trans-unit id="sys_action.hidden">
 				<source>Deactivated:</source>
 			</trans-unit>