diff --git a/src/decoration.h b/src/decoration.h
--- a/src/decoration.h
+++ b/src/decoration.h
@@ -27,6 +27,7 @@
 #include <QObject>
 #include <QPointer>
 #include <QRect>
+#include <QVector>
 
 class QHoverEvent;
 class QMouseEvent;
@@ -113,6 +114,20 @@
      **/
     QWeakPointer<DecoratedClient> client() const;
 
+    /**
+     * All @link{DecoratedClient}s for this Decoration in case window tabs are used.
+     * If no window tabs are used, this contains just the DecoratedClient returned by @link client.
+     * If window tabs are used the returned vector is in order of the tabs.
+     *
+     * If the tabs change (order, adding or removing tabs) the signal clientsChanged is emitted.
+     *
+     * Ownership of the @link{DecoratedClient}s is with the Decoration objects owning the
+     * Decoration.
+     * @since 5.14
+     * @see client
+     **/
+    QVector<DecoratedClient*> windowTabClients() const;
+
     QMargins borders() const;
     int borderLeft() const;
     int borderRight() const;
@@ -167,7 +182,18 @@
     bool event(QEvent *event) override;
 
 public Q_SLOTS:
+    /**
+     * Requests to close the window tab group.
+     * In case no window tabs are used only the DecoratedClient for this Decoration is requested to close.
+     * @see requestCloseWindowTab
+     **/
     void requestClose();
+    /**
+     * Requests to close the window tab referring to the DecoratedClient @p client.
+     * @see requestClose
+     * @since 5.14
+     **/
+    void requestCloseWindowTab(DecoratedClient *client);
     void requestToggleMaximization(Qt::MouseButtons buttons);
     void requestMinimize();
     void requestContextHelp();
@@ -178,6 +204,13 @@
     void requestShowWindowMenu();
     void requestShowToolTip(const QString &text);
     void requestHideToolTip();
+    /**
+     * Requests to activate the window tab @p client.
+     * Only a Decoration which contains the active DecoratedClient can request to activate
+     * another DecoratedClient in it's window tab group.
+     * @since 5.14
+     **/
+    void requestActivateWindowTab(DecoratedClient *client);
 
     void showApplicationMenu(int actionId);
     void requestShowApplicationMenu(const QRect &rect, int actionId);
@@ -201,6 +234,11 @@
     void titleBarChanged();
     void opaqueChanged(bool);
     void shadowChanged(const QSharedPointer<DecorationShadow> &shadow);
+    /**
+     * The vector returned by @link{windowTabClients} changed.
+     * @since 5.14
+     **/
+    void windowTabClientsChanged();
 
 protected:
     /**
diff --git a/src/decoration.cpp b/src/decoration.cpp
--- a/src/decoration.cpp
+++ b/src/decoration.cpp
@@ -169,7 +169,6 @@
     d->client->d->name(); \
 }
 
-DELEGATE(requestClose)
 DELEGATE(requestContextHelp)
 DELEGATE(requestMinimize)
 DELEGATE(requestToggleOnAllDesktops)
@@ -410,4 +409,33 @@
     return d->settings;
 }
 
+QVector<DecoratedClient*> Decoration::windowTabClients() const
+{
+    if (auto c = dynamic_cast<WindowTabsEnabledDecoratedClientPrivate *>(d->client->d.get())) {
+        return c->tabGroup();
+    }
+    return {d->client.data()};
+}
+
+void Decoration::requestClose()
+{
+    if (auto c = dynamic_cast<WindowTabsEnabledDecoratedClientPrivate *>(d->client->d.get())) {
+        c->requestCloseWindowTabGroup();
+    } else {
+        d->client->d->requestClose();
+    }
+}
+
+void Decoration::requestCloseWindowTab(DecoratedClient *client)
+{
+    client->d->requestClose();
+}
+
+void Decoration::requestActivateWindowTab(DecoratedClient *client)
+{
+    if (auto c = dynamic_cast<WindowTabsEnabledDecoratedClientPrivate *>(client->d.get())) {
+        return c->requestActivate();
+    }
+}
+
 } // namespace
diff --git a/src/private/decoratedclientprivate.h b/src/private/decoratedclientprivate.h
--- a/src/private/decoratedclientprivate.h
+++ b/src/private/decoratedclientprivate.h
@@ -25,6 +25,7 @@
 
 #include <QString>
 #include <QIcon>
+#include <QVector>
 
 //
 //  W A R N I N G
@@ -117,6 +118,32 @@
     explicit ApplicationMenuEnabledDecoratedClientPrivate(DecoratedClient *client, Decoration *decoration);
 };
 
+class KDECORATIONS_PRIVATE_EXPORT WindowTabsEnabledDecoratedClientPrivate : public ApplicationMenuEnabledDecoratedClientPrivate
+{
+public:
+    ~WindowTabsEnabledDecoratedClientPrivate() override;
+
+    /**
+     * All clients of the window tab group.
+     * In case there is only this DecoratedClient in the window tab group the returned vector should
+     * only contain this DecoratedClient.
+     **/
+    virtual QVector<DecoratedClient*> tabGroup() const = 0;
+
+    /**
+     * Requests to activate this DecoratedClient in the window tab group.
+     **/
+    virtual void requestActivate() = 0;
+
+    /**
+     * Requests to close all clients in the window tab group.
+     **/
+    virtual void requestCloseWindowTabGroup() = 0;
+
+protected:
+    explicit WindowTabsEnabledDecoratedClientPrivate(DecoratedClient *client, Decoration *decoration);
+};
+
 } // namespace
 
 #endif
diff --git a/src/private/decoratedclientprivate.cpp b/src/private/decoratedclientprivate.cpp
--- a/src/private/decoratedclientprivate.cpp
+++ b/src/private/decoratedclientprivate.cpp
@@ -71,9 +71,17 @@
 ApplicationMenuEnabledDecoratedClientPrivate::ApplicationMenuEnabledDecoratedClientPrivate(DecoratedClient *client, Decoration *decoration)
     : DecoratedClientPrivate(client, decoration)
 {
-
 }
 
 ApplicationMenuEnabledDecoratedClientPrivate::~ApplicationMenuEnabledDecoratedClientPrivate() = default;
 
+
+WindowTabsEnabledDecoratedClientPrivate::WindowTabsEnabledDecoratedClientPrivate(DecoratedClient *client, Decoration *decoration)
+    : ApplicationMenuEnabledDecoratedClientPrivate(client, decoration)
+{
+
+}
+
+WindowTabsEnabledDecoratedClientPrivate::~WindowTabsEnabledDecoratedClientPrivate() = default;
+
 }