diff --git a/src/transformers/pipelines.py b/src/transformers/pipelines.py
index b2399146a3b601..d9afaa1c12022f 100755
--- a/src/transformers/pipelines.py
+++ b/src/transformers/pipelines.py
@@ -1333,10 +1333,7 @@ class TokenClassificationArgumentHandler(ArgumentHandler):
     def __call__(self, *args, **kwargs):
 
         if args is not None and len(args) > 0:
-            if isinstance(args, str):
-                inputs = [args]
-            else:
-                inputs = args
+            inputs = list(args)
             batch_size = len(inputs)
         else:
             raise ValueError("At least one input is required.")
diff --git a/tests/test_pipelines_ner.py b/tests/test_pipelines_ner.py
index 3eb15e544d0ce4..bc12900d8422c3 100644
--- a/tests/test_pipelines_ner.py
+++ b/tests/test_pipelines_ner.py
@@ -1,7 +1,7 @@
 import unittest
 
 from transformers import AutoTokenizer, pipeline
-from transformers.pipelines import Pipeline
+from transformers.pipelines import Pipeline, TokenClassificationArgumentHandler
 from transformers.testing_utils import require_tf, require_torch
 
 from .test_pipelines_common import CustomInputPipelineCommonMixin
@@ -107,13 +107,9 @@ def _test_pipeline(self, nlp: Pipeline):
     def test_tf_only(self):
         model_name = "Narsil/small"  # This model only has a TensorFlow version
         # We test that if we don't specificy framework='tf', it gets detected automatically
-        tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
-        nlp = pipeline(task="ner", model=model_name, tokenizer=tokenizer)
+        nlp = pipeline(task="ner", model=model_name)
         self._test_pipeline(nlp)
 
-    #         offset=tokenizer(VALID_INPUTS[0],return_offsets_mapping=True)['offset_mapping']
-    #         pipeline_running_kwargs = {"offset_mapping"}  # Additional kwargs to run the pipeline with
-
     @require_tf
     def test_tf_defaults(self):
         for model_name in self.small_models:
@@ -122,9 +118,8 @@ def test_tf_defaults(self):
         self._test_pipeline(nlp)
 
     @require_tf
-    def test_tf_small(self):
+    def test_tf_small_ignore_subwords_available_for_fast_tokenizers(self):
         for model_name in self.small_models:
-            print(model_name)
             tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
             nlp = pipeline(
                 task="ner",
@@ -136,20 +131,20 @@ def test_tf_small(self):
             )
             self._test_pipeline(nlp)
 
-            for model_name in self.small_models:
-                tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
-                nlp = pipeline(
-                    task="ner",
-                    model=model_name,
-                    tokenizer=tokenizer,
-                    framework="tf",
-                    grouped_entities=True,
-                    ignore_subwords=False,
-                )
-                self._test_pipeline(nlp)
+        for model_name in self.small_models:
+            tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
+            nlp = pipeline(
+                task="ner",
+                model=model_name,
+                tokenizer=tokenizer,
+                framework="tf",
+                grouped_entities=True,
+                ignore_subwords=False,
+            )
+            self._test_pipeline(nlp)
 
     @require_torch
-    def test_pt_defaults_slow_tokenizer_raises(self):
+    def test_pt_ignore_subwords_slow_tokenizer_raises(self):
         for model_name in self.small_models:
             tokenizer = AutoTokenizer.from_pretrained(model_name)
 
@@ -166,12 +161,11 @@ def test_pt_defaults_slow_tokenizer(self):
     @require_torch
     def test_pt_defaults(self):
         for model_name in self.small_models:
-            tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
-            nlp = pipeline(task="ner", model=model_name, tokenizer=tokenizer)
+            nlp = pipeline(task="ner", model=model_name)
             self._test_pipeline(nlp)
 
     @require_torch
-    def test_torch_small(self):
+    def test_pt_small_ignore_subwords_available_for_fast_tokenizers(self):
         for model_name in self.small_models:
             tokenizer = AutoTokenizer.from_pretrained(model_name, use_fast=True)
             nlp = pipeline(
@@ -185,3 +179,46 @@ def test_torch_small(self):
                 task="ner", model=model_name, tokenizer=tokenizer, grouped_entities=True, ignore_subwords=False
             )
             self._test_pipeline(nlp)
+
+
+class TokenClassificationArgumentHandlerTestCase(unittest.TestCase):
+    def setUp(self):
+        self.args_parser = TokenClassificationArgumentHandler()
+
+    def test_simple(self):
+        string = "This is a simple input"
+
+        inputs, offset_mapping = self.args_parser(string)
+        self.assertEqual(inputs, [string])
+        self.assertEqual(offset_mapping, None)
+
+        inputs, offset_mapping = self.args_parser(string, string)
+        self.assertEqual(inputs, [string, string])
+        self.assertEqual(offset_mapping, None)
+
+        inputs, offset_mapping = self.args_parser(string, offset_mapping=[(0, 1), (1, 2)])
+        self.assertEqual(inputs, [string])
+        self.assertEqual(offset_mapping, [[(0, 1), (1, 2)]])
+
+        inputs, offset_mapping = self.args_parser(string, string, offset_mapping=[[(0, 1), (1, 2)], [(0, 2), (2, 3)]])
+        self.assertEqual(inputs, [string, string])
+        self.assertEqual(offset_mapping, [[(0, 1), (1, 2)], [(0, 2), (2, 3)]])
+
+    def test_errors(self):
+        string = "This is a simple input"
+
+        # 2 sentences, 1 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(string, string, offset_mapping=[[(0, 1), (1, 2)]])
+
+        # 2 sentences, 1 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(string, string, offset_mapping=[(0, 1), (1, 2)])
+
+        # 1 sentences, 2 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(string, offset_mapping=[[(0, 1), (1, 2)], [(0, 2), (2, 3)]])
+
+        # 0 sentences, 1 offset_mapping
+        with self.assertRaises(ValueError):
+            self.args_parser(offset_mapping=[[(0, 1), (1, 2)]])