diff --git a/crates/caldav/src/principal/mod.rs b/crates/caldav/src/principal/mod.rs
index 7f8a998..4a8f860 100644
--- a/crates/caldav/src/principal/mod.rs
+++ b/crates/caldav/src/principal/mod.rs
@@ -77,16 +77,23 @@ impl Resource for PrincipalResource {
         prop: &PrincipalPropWrapperName,
     ) -> Result<Self::Prop, Self::Error> {
         let principal_url = Self::get_url(rmap, vec![&self.principal]).unwrap();
+
         let home_set = CalendarHomeSet(
-            self.home_set
-                .iter()
-                .map(|&(home_name, _read_only)| format!("{}/{}", principal_url, home_name).into())
+            user.memberships()
+                .into_iter()
+                .map(|principal| Self::get_url(rmap, vec![principal]).unwrap())
+                .flat_map(|principal_url| {
+                    self.home_set.iter().map(move |&(home_name, _read_only)| {
+                        HrefElement::new(format!("{}/{}", &principal_url, home_name))
+                    })
+                })
                 .collect(),
         );
 
         Ok(match prop {
             PrincipalPropWrapperName::Principal(prop) => {
                 PrincipalPropWrapper::Principal(match prop {
+                    // TODO: principal types
                     PrincipalPropName::CalendarUserType => {
                         PrincipalProp::CalendarUserType("INDIVIDUAL")
                     }
diff --git a/crates/store/src/auth/user.rs b/crates/store/src/auth/user.rs
index ec85916..9569c3d 100644
--- a/crates/store/src/auth/user.rs
+++ b/crates/store/src/auth/user.rs
@@ -15,6 +15,8 @@ pub struct User {
     pub password: Option<String>,
     #[serde(default)]
     pub app_tokens: Vec<String>,
+    #[serde(default)]
+    pub memberships: Vec<String>,
 }
 
 impl User {
@@ -25,7 +27,16 @@ impl User {
         if self.id == principal {
             return true;
         }
-        false
+        self.memberships
+            .iter()
+            .any(|membership| membership == principal)
+    }
+
+    /// Returns all principals the user implements
+    pub fn memberships(&self) -> Vec<&str> {
+        let mut memberships: Vec<_> = self.memberships.iter().map(String::as_ref).collect();
+        memberships.push(self.id.as_str());
+        memberships
     }
 }
 
diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index 797d947..2dcc442 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -35,6 +35,10 @@ pub fn cmd_gen_config(_args: GenConfigArgs) -> anyhow::Result<()> {
                 app_tokens: vec![
                     "generate an app token hash with rustical pwhash --algorithm pbkdf2".to_owned(),
                 ],
+                memberships: vec![
+                    "Here you can specify other principals this principal should be a member of"
+                        .to_owned(),
+                ],
             }],
         }),
         data_store: DataStoreConfig::Sqlite(SqliteDataStoreConfig {