diff --git a/services/groupware/pkg/groupware/api_addressbooks.go b/services/groupware/pkg/groupware/api_addressbooks.go
index 6f169b81aa..e54e4c190b 100644
--- a/services/groupware/pkg/groupware/api_addressbooks.go
+++ b/services/groupware/pkg/groupware/api_addressbooks.go
@@ -158,3 +158,32 @@ func (g *Groupware) DeleteAddressBook(w http.ResponseWriter, r *http.Request) {
 		return req.noContent(accountId, sessionState, AddressBookResponseObjectType, state)
 	})
 }
+
+func (g *Groupware) ModifyAddressBook(w http.ResponseWriter, r *http.Request) {
+	g.respond(w, r, func(req Request) Response {
+		ok, accountId, resp := req.needContactWithAccount()
+		if !ok {
+			return resp
+		}
+		l := req.logger.With().Str(accountId, log.SafeString(accountId))
+		id, err := req.PathParamDoc(UriParamAddressBookId, "The unique identifier of the AddressBook to modify")
+		if err != nil {
+			return req.error(accountId, err)
+		}
+		l.Str(UriParamAddressBookId, log.SafeString(id))
+
+		var change jmap.AddressBookChange
+		err = req.body(&change)
+		if err != nil {
+			return req.error(accountId, err)
+		}
+
+		logger := log.From(l)
+		ctx := req.ctx.WithLogger(logger)
+		updated, sessionState, state, lang, jerr := g.jmap.UpdateAddressBook(accountId, id, change, ctx)
+		if jerr != nil {
+			return req.jmapError(accountId, jerr, sessionState, lang)
+		}
+		return req.respond(accountId, updated, sessionState, AddressBookResponseObjectType, state)
+	})
+}
diff --git a/services/groupware/pkg/groupware/api_calendars.go b/services/groupware/pkg/groupware/api_calendars.go
index d2a2af3dbd..02f9dc874e 100644
--- a/services/groupware/pkg/groupware/api_calendars.go
+++ b/services/groupware/pkg/groupware/api_calendars.go
@@ -95,7 +95,7 @@ func (g *Groupware) GetCalendarChanges(w http.ResponseWriter, r *http.Request) {
 
 func (g *Groupware) CreateCalendar(w http.ResponseWriter, r *http.Request) {
 	g.respond(w, r, func(req Request) Response {
-		ok, accountId, resp := req.needContactWithAccount()
+		ok, accountId, resp := req.needCalendarWithAccount()
 		if !ok {
 			return resp
 		}
@@ -120,7 +120,7 @@ func (g *Groupware) CreateCalendar(w http.ResponseWriter, r *http.Request) {
 
 func (g *Groupware) DeleteCalendar(w http.ResponseWriter, r *http.Request) {
 	g.respond(w, r, func(req Request) Response {
-		ok, accountId, resp := req.needContactWithAccount()
+		ok, accountId, resp := req.needCalendarWithAccount()
 		if !ok {
 			return resp
 		}
@@ -157,3 +157,32 @@ func (g *Groupware) DeleteCalendar(w http.ResponseWriter, r *http.Request) {
 		return req.noContent(accountId, sessionState, CalendarResponseObjectType, state)
 	})
 }
+
+func (g *Groupware) ModifyCalendar(w http.ResponseWriter, r *http.Request) {
+	g.respond(w, r, func(req Request) Response {
+		ok, accountId, resp := req.needCalendarWithAccount()
+		if !ok {
+			return resp
+		}
+		l := req.logger.With().Str(accountId, log.SafeString(accountId))
+		id, err := req.PathParamDoc(UriParamCalendarId, "The unique identifier of the Calendar to modify")
+		if err != nil {
+			return req.error(accountId, err)
+		}
+		l.Str(UriParamCalendarId, log.SafeString(id))
+
+		var change jmap.CalendarChange
+		err = req.body(&change)
+		if err != nil {
+			return req.error(accountId, err)
+		}
+
+		logger := log.From(l)
+		ctx := req.ctx.WithLogger(logger)
+		updated, sessionState, state, lang, jerr := g.jmap.UpdateCalendar(accountId, id, change, ctx)
+		if jerr != nil {
+			return req.jmapError(accountId, jerr, sessionState, lang)
+		}
+		return req.respond(accountId, updated, sessionState, CalendarResponseObjectType, state)
+	})
+}
diff --git a/services/groupware/pkg/groupware/api_contacts.go b/services/groupware/pkg/groupware/api_contacts.go
index b7aeedc1ca..ebceefde6a 100644
--- a/services/groupware/pkg/groupware/api_contacts.go
+++ b/services/groupware/pkg/groupware/api_contacts.go
@@ -258,6 +258,35 @@ func (g *Groupware) DeleteContact(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+func (g *Groupware) ModifyContact(w http.ResponseWriter, r *http.Request) {
+	g.respond(w, r, func(req Request) Response {
+		ok, accountId, resp := req.needContactWithAccount()
+		if !ok {
+			return resp
+		}
+		l := req.logger.With().Str(accountId, log.SafeString(accountId))
+		id, err := req.PathParamDoc(UriParamContactId, "The unique identifier of the Contact to modify")
+		if err != nil {
+			return req.error(accountId, err)
+		}
+		l.Str(UriParamContactId, log.SafeString(id))
+
+		var change jmap.ContactCardChange
+		err = req.body(&change)
+		if err != nil {
+			return req.error(accountId, err)
+		}
+
+		logger := log.From(l)
+		ctx := req.ctx.WithLogger(logger)
+		updated, sessionState, state, lang, jerr := g.jmap.UpdateContactCard(accountId, id, change, ctx)
+		if jerr != nil {
+			return req.jmapError(accountId, jerr, sessionState, lang)
+		}
+		return req.respond(accountId, updated, sessionState, ContactResponseObjectType, state)
+	})
+}
+
 func mapContactCardSort(s SortCrit) jmap.ContactCardComparator {
 	attr := s.Attribute
 	if mapped, ok := ContactSortingPropertyMapping[s.Attribute]; ok {
diff --git a/services/groupware/pkg/groupware/api_events.go b/services/groupware/pkg/groupware/api_events.go
index 431febd46b..4c2195687c 100644
--- a/services/groupware/pkg/groupware/api_events.go
+++ b/services/groupware/pkg/groupware/api_events.go
@@ -159,6 +159,35 @@ func (g *Groupware) DeleteCalendarEvent(w http.ResponseWriter, r *http.Request)
 	})
 }
 
+func (g *Groupware) ModifyCalendarEvent(w http.ResponseWriter, r *http.Request) {
+	g.respond(w, r, func(req Request) Response {
+		ok, accountId, resp := req.needCalendarWithAccount()
+		if !ok {
+			return resp
+		}
+		l := req.logger.With().Str(accountId, log.SafeString(accountId))
+		id, err := req.PathParamDoc(UriParamEventId, "The unique identifier of the Calendar Event to modify")
+		if err != nil {
+			return req.error(accountId, err)
+		}
+		l.Str(UriParamEventId, log.SafeString(id))
+
+		var change jmap.CalendarEventChange
+		err = req.body(&change)
+		if err != nil {
+			return req.error(accountId, err)
+		}
+
+		logger := log.From(l)
+		ctx := req.ctx.WithLogger(logger)
+		updated, sessionState, state, lang, jerr := g.jmap.UpdateCalendarEvent(accountId, id, change, ctx)
+		if jerr != nil {
+			return req.jmapError(accountId, jerr, sessionState, lang)
+		}
+		return req.respond(accountId, updated, sessionState, EventResponseObjectType, state)
+	})
+}
+
 // Parse a blob that contains an iCal file and return it as JSCalendar.
 //
 // @api:tags calendar,blob
diff --git a/services/groupware/pkg/groupware/route.go b/services/groupware/pkg/groupware/route.go
index 96667614e5..3edbad2681 100644
--- a/services/groupware/pkg/groupware/route.go
+++ b/services/groupware/pkg/groupware/route.go
@@ -151,8 +151,9 @@ func (g *Groupware) Route(r chi.Router) {
 				r.Post("/", g.CreateAddressBook)
 				r.Route("/{addressbookid}", func(r chi.Router) {
 					r.Get("/", g.GetAddressbook)
-					r.Get("/contacts", g.GetContactsInAddressbook) //NOSONAR
+					r.Patch("/", g.ModifyAddressBook)
 					r.Delete("/", g.DeleteAddressBook)
+					r.Get("/contacts", g.GetContactsInAddressbook) //NOSONAR
 				})
 			})
 			r.Route("/contacts", func(r chi.Router) {
@@ -160,6 +161,7 @@ func (g *Groupware) Route(r chi.Router) {
 				r.Post("/", g.CreateContact)
 				r.Route("/{contactid}", func(r chi.Router) {
 					r.Get("/", g.GetContactById)
+					r.Patch("/", g.ModifyContact)
 					r.Delete("/", g.DeleteContact)
 				})
 			})
@@ -168,12 +170,14 @@ func (g *Groupware) Route(r chi.Router) {
 				r.Post("/", g.CreateCalendar)
 				r.Route("/{calendarid}", func(r chi.Router) {
 					r.Get("/", g.GetCalendarById)
-					r.Get("/events", g.GetEventsInCalendar) //NOSONAR
+					r.Patch("/", g.ModifyCalendar)
 					r.Delete("/", g.DeleteCalendar)
+					r.Get("/events", g.GetEventsInCalendar) //NOSONAR
 				})
 			})
 			r.Route("/events", func(r chi.Router) {
 				r.Post("/", g.CreateCalendarEvent)
+				r.Patch("/", g.ModifyCalendarEvent)
 				r.Delete("/{eventid}", g.DeleteCalendarEvent)
 			})
 			r.Route("/tasklists", func(r chi.Router) {
@@ -194,8 +198,10 @@ func (g *Groupware) Route(r chi.Router) {
 				// r.Get("/quotas", g.GetQuotaChanges)
 				r.Get("/identities", g.GetIdentityChanges)
 			})
-			r.Get("/objects", g.GetObjects)
-			r.Post("/objects", g.GetObjects)
+			r.Route("/objects", func(r chi.Router) {
+				r.Get("/", g.GetObjects)
+				r.Post("/", g.GetObjects) // this is actually a read-only operation
+			})
 		})
 	})