diff --git a/LeStorage/Relationship.swift b/LeStorage/Relationship.swift
index 7b0fe17..2955660 100644
--- a/LeStorage/Relationship.swift
+++ b/LeStorage/Relationship.swift
@@ -5,12 +5,18 @@
 //  Created by Laurent Morvillier on 27/11/2024.
 //
 
+public enum StoreLookup {
+    case same
+    case main
+    case child
+}
+
 public struct Relationship {
     
-    public init(type: any Storable.Type, keyPath: AnyKeyPath, mainStoreLookup: Bool) {
+    public init(type: any Storable.Type, keyPath: AnyKeyPath, storeLookup: StoreLookup) {
         self.type = type
         self.keyPath = keyPath
-        self.mainStoreLookup = mainStoreLookup
+        self.storeLookup = storeLookup
     }
     
     /// The type of the relationship
@@ -20,6 +26,6 @@ public struct Relationship {
     var keyPath: AnyKeyPath
     
     /// Indicates whether the linked object is on the main Store
-    var mainStoreLookup: Bool
+    var storeLookup: StoreLookup
     
 }
diff --git a/LeStorage/Store.swift b/LeStorage/Store.swift
index 1a5a3b8..747aa34 100644
--- a/LeStorage/Store.swift
+++ b/LeStorage/Store.swift
@@ -19,6 +19,7 @@ public enum StoreError: Error, LocalizedError {
     case synchronizationInactive
     case storeNotRegistered(id: String)
     case castIssue(type: String)
+    case invalidStoreLookup(from: any Storable.Type, to: any Storable.Type)
     
     public var errorDescription: String? {
         switch self {
@@ -42,6 +43,8 @@ public enum StoreError: Error, LocalizedError {
             return "The store with identifier \(id) is not registered"
         case .castIssue(let type):
             return "Can't cast to \(type)"
+        case .invalidStoreLookup(let from, let to):
+            return "invalid store lookup from \(from) to \(to)"
         }
     }
     
@@ -275,19 +278,27 @@ final public class Store {
     }
     
     /// Calls deleteById from the collection corresponding to the instance
-    func referenceCount<T: SyncedStorable>(type: T.Type, id: String) -> Int {
-        var count: Int = 0
-        for collection in self._collections.values {
-            count += collection.referenceCount(type: type, id: id)
+//    func referenceCount<T: SyncedStorable>(type: T.Type, id: String) -> Int {
+//        var count: Int = 0
+//        for collection in self._collections.values {
+//            count += collection.referenceCount(type: type, id: id)
+//        }
+//        return count
+//    }
+    
+    func isReferenced<T: Storable, S: Storable>(collectionType: S.Type, type: T.Type, id: String) -> Bool {
+        if let collection = self._baseCollections[S.resourceName()] {
+            return collection.isReferenced(type: type, id: id)
+        } else {
+            return false
         }
-        return count
     }
     
-    public func deleteUnusedSharedIfNecessary<T: SyncedStorable>(_ instance: T) {
-        if self.referenceCount(type: T.self, id: instance.stringId) == 0 {
+    public func deleteUnusedGrantedIfNecessary<T: SyncedStorable>(_ instance: T, originStoreId: String?) {
+        if !self.storeCenter.isReferenced(instance: instance) {
             do {
                 let collection: SyncedCollection<T> = try self.syncedCollection()
-                collection.deleteUnusedShared(instance: instance)
+                collection.deleteUnusedGranted(instance: instance)
             } catch {
                 Logger.error(error)
             }
@@ -320,11 +331,11 @@ final public class Store {
         do {
             for item in items {
                 guard item.sharing != nil else { continue }
-                if self.referenceCount(type: T.self, id: item.stringId) == 0 {
+                if !self.storeCenter.isReferenced(instance: item) {
                     // Only delete if the shared item has no references
                     item.deleteUnusedSharedDependencies(store: self)
                     let collection: SyncedCollection<T> = try self.syncedCollection()
-                    collection.deleteUnusedShared(instance: item)
+                    collection.deleteUnusedGranted(instance: item)
                 }
             }
         } catch {
diff --git a/LeStorage/StoreCenter.swift b/LeStorage/StoreCenter.swift
index 9ae0c6c..612e3b3 100644
--- a/LeStorage/StoreCenter.swift
+++ b/LeStorage/StoreCenter.swift
@@ -227,7 +227,7 @@ public class StoreCenter {
         }
     }
     
-    fileprivate func _store(id: String?) -> Store? {
+    fileprivate func _store(id: String?) -> Store {
         if let storeId = id, let store = self._stores[storeId] {
             return store
         } else {
@@ -782,7 +782,7 @@ public class StoreCenter {
     @MainActor
     func synchronizationDelete<T: SyncedStorable>(id: String, type: T.Type, storeId: String?) {
         do {
-            try self._store(id: storeId)?.deleteNoSyncNoCascade(type: type, id: id)
+            try self._store(id: storeId).deleteNoSyncNoCascade(type: type, id: id)
         } catch {
             Logger.error(error)
         }
@@ -794,23 +794,34 @@ public class StoreCenter {
     func synchronizationRevoke<T: SyncedStorable>(id: String, type: T.Type, storeId: String?) {
         
         do {
-            if self._instanceShared(id: id, type: type) {
-                let count = self.mainStore.referenceCount(type: type, id: id)
-                if count == 0 {
-                    try self._store(id: storeId)?.deleteNoSyncNoCascade(type: type, id: id)
+            if let instance = self._instance(id: id, type: type, storeId: storeId) {
+                if instance.sharing != nil && !self.isReferenced(instance: instance) {
+                    try self._store(id: storeId).deleteNoSyncNoCascade(type: type, id: id)
                 }
             }
+            
+//            if self._instanceShared(id: id, type: type, storeId: storeId) {
+//                let count = self.isReferenced(type: type, id: id)
+//                if count == 0 {
+//                    try self._store(id: storeId).deleteNoSyncNoCascade(type: type, id: id)
+//                }
+//            }
         } catch {
             Logger.error(error)
         }
     }
     
-    /// Returns whether an instance has been shared with the user
-    fileprivate func _instanceShared<T: SyncedStorable>(id: String, type: T.Type) -> Bool {
+    fileprivate func _instance<T: SyncedStorable>(id: String, type: T.Type, storeId: String?) -> T? {
         let realId: T.ID = T.buildRealId(id: id)
-        let instance: T? = self.mainStore.findById(realId)
-        return instance?.sharing != nil
+        return self._store(id: storeId).findById(realId)
     }
+    
+    /// Returns whether an instance has been shared with the user
+//    fileprivate func _instanceShared<T: SyncedStorable>(id: String, type: T.Type, storeId: String?) -> Bool {
+////        let realId: T.ID = T.buildRealId(id: id)
+//        let instance: T? = self._instance(id: id, type: type, storeId: storeId)
+//        return instance?.sharing != nil
+//    }
 
     /// Deletes a data log by data id
     fileprivate func _cleanupDataLog(dataId: String) {
@@ -826,6 +837,28 @@ public class StoreCenter {
         self._deleteLogs.addOrUpdate(instance: dataLog)
     }
 
+    func relationshipStore<T: SyncedStorable>(instance: T, relationship: Relationship) -> Store? {
+        switch relationship.storeLookup {
+        case .main: return Store.main
+        case .child: return self._stores[instance.stringId]
+        case .same: return instance.store
+        }
+    }
+    
+    func isReferenced<T: SyncedStorable>(instance: T) -> Bool {
+        let relationships = T.relationships()
+        for relationship in relationships {
+            if let store = self.relationshipStore(instance: instance, relationship: relationship) {
+                if store.isReferenced(collectionType: relationship.type, type: T.self, id: instance.stringId) {
+                    return true
+                }
+            } else {
+                Logger.w("missing store for instance \(instance)")
+            }
+        }
+        return false
+    }
+
     // MARK: - Sync data conversion
     
     func decodeObjectIdentifierDictionary(_ dictionary: [String: Any]) throws -> [ObjectIdentifierArray] {
diff --git a/LeStorage/StoredCollection.swift b/LeStorage/StoredCollection.swift
index 2cb8dd7..11c48ea 100644
--- a/LeStorage/StoredCollection.swift
+++ b/LeStorage/StoredCollection.swift
@@ -17,7 +17,7 @@ public protocol SomeCollection<Item>: Identifiable {
     var type: any Storable.Type { get }
 
     func reset()
-    func referenceCount<S: Storable>(type: S.Type, id: String) -> Int
+    func isReferenced<S: Storable>(type: S.Type, id: String) -> Bool
 
     var items: [Item] { get }
     
@@ -528,16 +528,25 @@ public class StoredCollection<T: Storable>: SomeCollection {
     // MARK: - Reference count
 
     /// Counts the references to an object - given its type and id - inside the collection
-    public func referenceCount<S: Storable>(type: S.Type, id: String) -> Int {
+    public func isReferenced<S: Storable>(type: S.Type, id: String) -> Bool {
         let relationships = T.relationships().filter { $0.type == type }
-        guard relationships.count > 0 else { return 0 }
+        guard relationships.count > 0 else { return false }
 
-        return self.items.reduce(0) { count, item in
-            count
-                + relationships.filter { relationship in
-                    (item[keyPath: relationship.keyPath] as? String) == id
-                }.count
+        for item in self.items {
+            for relationship in relationships {
+                if item[keyPath: relationship.keyPath] as? String == id {
+                    return true
+                }
+            }
         }
+        return false
+        
+//        return self.items.reduce(0) { count, item in
+//            count
+//                + relationships.filter { relationship in
+//                    (item[keyPath: relationship.keyPath] as? String) == id
+//                }.count
+//        }
     }
     
     // MARK: - for Synced Collection
diff --git a/LeStorage/SyncedCollection.swift b/LeStorage/SyncedCollection.swift
index 961a876..eeb4178 100644
--- a/LeStorage/SyncedCollection.swift
+++ b/LeStorage/SyncedCollection.swift
@@ -229,7 +229,7 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         for relationship in T.relationships() {
             if let syncedType = relationship.type as? (any SyncedStorable.Type) {
                 do {
-                    try self._deleteUnusedSharedInstances(relationship: relationship, type: syncedType)
+                    try self._deleteUnusedSharedInstances(relationship: relationship, type: syncedType, originStoreId: self.storeId)
                 } catch {
                     Logger.error(error)
                 }
@@ -237,24 +237,31 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         }
     }
     
-    fileprivate func _deleteUnusedSharedInstances<S: SyncedStorable>(relationship: Relationship, type: S.Type) throws {
+    fileprivate func _deleteUnusedSharedInstances<S: SyncedStorable>(relationship: Relationship, type: S.Type, originStoreId: String?) throws {
         
         let store: Store
-        if relationship.mainStoreLookup {
-            store = self.store.storeCenter.mainStore
-        } else {
-            store = self.store
+        switch relationship.storeLookup {
+        case .main: store = self.store.storeCenter.mainStore
+        case .same: store = self.store
+        case .child:
+            throw StoreError.invalidStoreLookup(from: type, to: relationship.type)
         }
+//        if relationship.storeLookup {
+//            store = self.store.storeCenter.mainStore
+//        } else {
+//            store = self.store
+//        }
 
         let collection: SyncedCollection<S> = try store.syncedCollection()
-        collection._deleteUnusedSharedInstances()
+        collection._deleteUnusedGrantedInstances(originStoreId: originStoreId)
     }
     
-    fileprivate func _deleteUnusedSharedInstances() {
+    fileprivate func _deleteUnusedGrantedInstances(originStoreId: String?) {
         
-        let sharedItems = self.collection.items.filter { $0.sharing != nil }
+        let sharedItems = self.collection.items.filter { $0.sharing == .granted }
         for sharedItem in sharedItems {
-            self.store.deleteUnusedSharedIfNecessary(sharedItem)
+            self.store.deleteUnusedGrantedIfNecessary(sharedItem, originStoreId: originStoreId
+            )
         }
     }
     
@@ -329,7 +336,7 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         self.collection.delete(contentOfs: sequence)
     }
     
-    func deleteUnusedShared(instance: T) {
+    func deleteUnusedGranted(instance: T) {
         
         guard instance.sharing != nil else { return }
         
@@ -451,8 +458,8 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
     
     public var type: any Storable.Type { return T.self }
     
-    public func referenceCount<S>(type: S.Type, id: String) -> Int where S : Storable {
-        return self.collection.referenceCount(type: type, id: id)
+    public func isReferenced<S>(type: S.Type, id: String) -> Bool where S : Storable {
+        return self.collection.isReferenced(type: type, id: id)
     }
     
     public func reset() {