diff --git a/crates/caldav/src/calendar/resource.rs b/crates/caldav/src/calendar/resource.rs
index 65d5912..c3e9fea 100644
--- a/crates/caldav/src/calendar/resource.rs
+++ b/crates/caldav/src/calendar/resource.rs
@@ -17,6 +17,7 @@ use rustical_store::auth::Principal;
 use rustical_xml::{EnumVariants, PropName};
 use rustical_xml::{XmlDeserialize, XmlSerialize};
 use serde::Deserialize;
+use std::borrow::Cow;
 
 #[derive(XmlDeserialize, XmlSerialize, PartialEq, Eq, Clone, EnumVariants, PropName)]
 #[xml(unit_variants_ident = "CalendarPropName")]
@@ -72,8 +73,8 @@ pub struct CalendarResource {
 }
 
 impl ResourceName for CalendarResource {
-    fn get_name(&self) -> String {
-        self.cal.id.clone()
+    fn get_name(&self) -> Cow<'_, str> {
+        Cow::from(&self.cal.id)
     }
 }
 
diff --git a/crates/caldav/src/calendar_object/resource.rs b/crates/caldav/src/calendar_object/resource.rs
index 15af050..475f1fa 100644
--- a/crates/caldav/src/calendar_object/resource.rs
+++ b/crates/caldav/src/calendar_object/resource.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use super::prop::{
     CalendarData, CalendarObjectProp, CalendarObjectPropName, CalendarObjectPropWrapper,
     CalendarObjectPropWrapperName,
@@ -20,8 +22,8 @@ pub struct CalendarObjectResource {
 }
 
 impl ResourceName for CalendarObjectResource {
-    fn get_name(&self) -> String {
-        format!("{}.ics", self.object.get_id())
+    fn get_name(&self) -> Cow<'_, str> {
+        Cow::from(format!("{}.ics", self.object.get_id()))
     }
 }
 
diff --git a/crates/caldav/src/principal/mod.rs b/crates/caldav/src/principal/mod.rs
index 728765b..9662dd9 100644
--- a/crates/caldav/src/principal/mod.rs
+++ b/crates/caldav/src/principal/mod.rs
@@ -6,6 +6,7 @@ use rustical_dav::xml::{
     GroupMemberSet, GroupMembership, Resourcetype, ResourcetypeInner, SupportedReportSet,
 };
 use rustical_store::auth::Principal;
+use std::borrow::Cow;
 
 mod service;
 pub use service::*;
@@ -23,8 +24,8 @@ pub struct PrincipalResource {
 }
 
 impl ResourceName for PrincipalResource {
-    fn get_name(&self) -> String {
-        self.principal.id.clone()
+    fn get_name(&self) -> Cow<'_, str> {
+        Cow::from(&self.principal.id)
     }
 }
 
diff --git a/crates/carddav/src/address_object/resource.rs b/crates/carddav/src/address_object/resource.rs
index 490a74d..cddcee3 100644
--- a/crates/carddav/src/address_object/resource.rs
+++ b/crates/carddav/src/address_object/resource.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use crate::{
     Error,
     address_object::{
@@ -22,8 +24,8 @@ pub struct AddressObjectResource {
 }
 
 impl ResourceName for AddressObjectResource {
-    fn get_name(&self) -> String {
-        format!("{}.vcf", self.object.get_id())
+    fn get_name(&self) -> Cow<'_, str> {
+        Cow::from(format!("{}.vcf", self.object.get_id()))
     }
 }
 
diff --git a/crates/carddav/src/addressbook/resource.rs b/crates/carddav/src/addressbook/resource.rs
index fcaea04..94ca550 100644
--- a/crates/carddav/src/addressbook/resource.rs
+++ b/crates/carddav/src/addressbook/resource.rs
@@ -11,13 +11,14 @@ use rustical_dav::xml::{Resourcetype, ResourcetypeInner, SupportedReportSet};
 use rustical_dav_push::DavPushExtension;
 use rustical_store::Addressbook;
 use rustical_store::auth::Principal;
+use std::borrow::Cow;
 
 #[derive(Clone, Debug, From, Into)]
 pub struct AddressbookResource(pub(crate) Addressbook);
 
 impl ResourceName for AddressbookResource {
-    fn get_name(&self) -> String {
-        self.0.id.clone()
+    fn get_name(&self) -> Cow<'_, str> {
+        Cow::from(&self.0.id)
     }
 }
 
diff --git a/crates/carddav/src/principal/mod.rs b/crates/carddav/src/principal/mod.rs
index e6f428a..89f4423 100644
--- a/crates/carddav/src/principal/mod.rs
+++ b/crates/carddav/src/principal/mod.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use crate::Error;
 use rustical_dav::extensions::CommonPropertiesExtension;
 use rustical_dav::privileges::UserPrivilegeSet;
@@ -21,8 +23,8 @@ pub struct PrincipalResource {
 }
 
 impl ResourceName for PrincipalResource {
-    fn get_name(&self) -> String {
-        self.principal.id.clone()
+    fn get_name(&self) -> Cow<'_, str> {
+        Cow::from(&self.principal.id)
     }
 }
 
diff --git a/crates/dav/src/resource/mod.rs b/crates/dav/src/resource/mod.rs
index 5d4f7ed..fcfc773 100644
--- a/crates/dav/src/resource/mod.rs
+++ b/crates/dav/src/resource/mod.rs
@@ -11,6 +11,7 @@ pub use resource_service::ResourceService;
 use rustical_xml::{
     EnumVariants, NamespaceOwned, PropName, XmlDeserialize, XmlDocument, XmlSerialize,
 };
+use std::borrow::Cow;
 use std::str::FromStr;
 
 mod axum_methods;
@@ -30,7 +31,7 @@ pub trait ResourcePropName: FromStr {}
 impl<T: FromStr> ResourcePropName for T {}
 
 pub trait ResourceName {
-    fn get_name(&self) -> String;
+    fn get_name(&self) -> Cow<'_, str>;
 }
 
 pub trait Resource: Clone + Send + 'static {