--- a/pallets/proxy-rmrk-core/src/lib.rs
+++ b/pallets/proxy-rmrk-core/src/lib.rs
@@ -161,7 +161,8 @@
 
             ensure!(collection.total_supply() == 0, <Error<T>>::CollectionNotEmpty);
 
-            <PalletNft<T>>::destroy_collection(collection, &cross_sender)?;
+            <PalletNft<T>>::destroy_collection(collection, &cross_sender)
+                .map_err(Self::map_common_err_to_proxy)?;
 
             Self::deposit_event(Event::CollectionDestroyed { issuer: sender, collection_id });
 
@@ -208,8 +209,9 @@
                 collection_id.into(),
                 CollectionType::Regular
             )?;
-            collection.check_is_owner(&cross_sender)?;
 
+            Self::check_collection_owner(&collection, &cross_sender)?;
+
             let token_count = collection.total_supply();
 
             let mut collection = collection.into_inner();
@@ -295,14 +297,7 @@
             &sender,
             data,
             &budget,
-        ).map_err(|err| {
-            map_common_err_to_proxy!(
-                match err {
-                    NoPermission => NoPermission,
-                    CollectionTokenLimitExceeded => CollectionFullOrLocked
-                }
-            )
-        })?;
+        ).map_err(Self::map_common_err_to_proxy)?;
 
         let nft_id = <PalletNft<T>>::current_token_id(&collection);
 
@@ -322,16 +317,23 @@
         sender: T::AccountId,
         new_owner: T::AccountId,
     ) -> DispatchResult {
-        let mut collection = Self::get_typed_nft_collection(
+        let collection = Self::get_typed_nft_collection(
             collection_id,
             collection_type
-        )?.into_inner();
-        collection.check_is_owner(&T::CrossAccountId::from_sub(sender))?;
+        )?;
+        Self::check_collection_owner(&collection, &T::CrossAccountId::from_sub(sender))?;
 
+        let mut collection = collection.into_inner();
+
         collection.owner = new_owner;
         collection.save()
     }
 
+    fn check_collection_owner(collection: &NonfungibleHandle<T>, account: &T::CrossAccountId) -> DispatchResult {
+        collection.check_is_owner(account)
+            .map_err(Self::map_common_err_to_proxy)
+    }
+
     pub fn get_nft_collection(collection_id: CollectionId) -> Result<NonfungibleHandle<T>, DispatchError> {
         let collection = <CollectionHandle<T>>::try_get(collection_id)
             .map_err(|_| <Error<T>>::CollectionUnknown)?
@@ -382,4 +384,13 @@
 
         Self::get_nft_collection(collection_id)
     }
+
+    fn map_common_err_to_proxy(err: DispatchError) -> DispatchError {
+        map_common_err_to_proxy! {
+            match err {
+                NoPermission => NoPermission,
+                CollectionTokenLimitExceeded => CollectionFullOrLocked
+            }
+        }
+    }
 }