diff --git a/CHANGES.rst b/CHANGES.rst
index e4e389fa..4927f472 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -62,7 +62,7 @@ Unreleased
   * :exc:`EntryMetadataNotFoundError`
   * the :attr:`~Entry.object_id` property of data objects and related exceptions
 
-* Make some of the parameters of the following positional-only:
+* Make some of the parameters of the following positional-only (:issue:`268`):
 
   * :meth:`Reader.add_feed`: ``feed``
   * :meth:`Reader.delete_feed`: ``feed``
@@ -94,6 +94,11 @@ Unreleased
   * :exc:`EntryError` (and subclasses): ``feed_url``, ``entry_id``
   * :exc:`TagError` (and subclasses): ``resource_id``, ``key``
 
+* Swap the order of the first two arguments of :exc:`TagError` (and subclasses);
+  ``TagError(key, resource_id, ...)`` becomes
+  ``TagError(resource_id, key, ...)``.
+  (:issue:`268`)
+
 
 Version 2.17
 ------------
diff --git a/src/reader/_storage.py b/src/reader/_storage.py
index 7b17bcbf..03c8108c 100644
--- a/src/reader/_storage.py
+++ b/src/reader/_storage.py
@@ -1139,7 +1139,7 @@ def delete_tag(self, resource_id: ResourceId, key: str) -> None:
 
         with self.get_db() as db:
             cursor = db.execute(query, params)
-        rowcount_exactly_one(cursor, lambda: TagNotFoundError(key, resource_id))
+        rowcount_exactly_one(cursor, lambda: TagNotFoundError(resource_id, key))
 
 
 def make_get_feeds_query(
diff --git a/src/reader/core.py b/src/reader/core.py
index e38eb3b0..0f918d4c 100644
--- a/src/reader/core.py
+++ b/src/reader/core.py
@@ -1958,7 +1958,7 @@ def get_tag(
         resource_id = _resource_argument(resource)
         return zero_or_one(
             (v for _, v in self._storage.get_tags(resource_id, key)),
-            lambda: TagNotFoundError(key, resource_id),
+            lambda: TagNotFoundError(resource_id, key),
             default,
         )
 
diff --git a/src/reader/exceptions.py b/src/reader/exceptions.py
index 61b9289b..b3af3c4b 100644
--- a/src/reader/exceptions.py
+++ b/src/reader/exceptions.py
@@ -229,25 +229,29 @@ class TagError(ReaderError):
     .. versionadded:: 2.8
 
     .. versionchanged:: 2.17
-        Signature changed from ``TagError(key, object_id, message='')``
-        to ``TagError(key, resource_id, message='')``.
+        Signature changed from ``TagError(key, object_id, ...)``
+        to ``TagError(key, resource_id, ...)``.
 
     .. versionchanged:: 3.0
-        The ``key`` and ``resource_id`` arguments are now positional-only.
+        Signature changed from ``TagError(key, resource_id, ...)``
+        to ``TagError(resource_id, key, ...)``.
+
+    .. versionchanged:: 3.0
+        The ``resource_id`` and ``key`` arguments are now positional-only.
 
     """
 
     def __init__(
-        self, key: str, resource_id: Tuple[str, ...], /, message: str = ''
+        self, resource_id: Tuple[str, ...], key: str, /, message: str = ''
     ) -> None:
         super().__init__(message)
 
-        #: The tag key.
-        self.key = key
-
         #: The `resource_id` of the resource.
         self.resource_id = resource_id
 
+        #: The tag key.
+        self.key = key
+
     @property
     def _str(self) -> str:
         parts = self.resource_id + (self.key,)
diff --git a/tests/test_exceptions.py b/tests/test_exceptions.py
index 390d3228..b661a656 100644
--- a/tests/test_exceptions.py
+++ b/tests/test_exceptions.py
@@ -66,5 +66,5 @@ def test_entry_error_str(exc_type):
 
 @pytest.mark.parametrize('exc_type', all_classes(TagError))
 def test_tag_error_str(exc_type):
-    exc = exc_type('key', ('object',))
+    exc = exc_type(('object',), 'key')
     assert "'object': 'key'" in str(exc)