diff --git a/exoscale/api/exceptions.py b/exoscale/api/exceptions.py
index 569b643..67ad778 100644
--- a/exoscale/api/exceptions.py
+++ b/exoscale/api/exceptions.py
@@ -34,4 +34,4 @@ class ExoscaleAPIAuthException(ExoscaleAPIException):
     Shows the server encountered an error while processing the request.
     """
 
-    pass
\ No newline at end of file
+    pass
diff --git a/exoscale/api/v2.py b/exoscale/api/v2.py
index 3983afa..4b6ddcd 100644
--- a/exoscale/api/v2.py
+++ b/exoscale/api/v2.py
@@ -27,7 +27,11 @@
 from pathlib import Path
 
 from exoscale_auth import ExoscaleV2Auth
-from .exceptions import ExoscaleAPIAuthException, ExoscaleAPIClientException, ExoscaleAPIServerException
+from .exceptions import (
+    ExoscaleAPIAuthException,
+    ExoscaleAPIClientException,
+    ExoscaleAPIServerException,
+)
 
 import requests
 
@@ -158,7 +162,7 @@ def _call_operation(self, operation_id, parameters=None, body=None):
         )
 
         # Error handling
-        if response.status_code == 403 :
+        if response.status_code == 403:
             raise ExoscaleAPIAuthException(
                 f"Authentication error {response.status_code}: {response.text}"
             )
diff --git a/tests/test_client.py b/tests/test_client.py
index 9e10cb5..bdd0d9c 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -2,6 +2,12 @@
 
 from exoscale.api.v2 import Client
 
+from exoscale.api.exceptions import (
+    ExoscaleAPIClientException,
+    ExoscaleAPIServerException,
+    ExoscaleAPIAuthException,
+)
+
 
 def test_client_creation():
     c = Client("key", "secret", zone="at-vie-1")
@@ -20,3 +26,54 @@ def test_client_creation():
     # create with custom URL
     c = Client("key", "secret", url="http://localhost:8000/v2")
     assert hasattr(c, "list_zones")
+
+
+def test_client_error_handling(requests_mock):
+    client = Client(key="EXOtest", secret="sdsd")
+
+    # Mock a 403 authentication error
+    requests_mock.get(
+        "https://api-ch-gva-2.exoscale.com/v2/instance/85664334-0fd5-47bd-94a1-b4f40b1d2eb7",
+        status_code=403,
+        text='{"message":"Invalid request signature"}',
+    )
+    try:
+        client_with_wrong_key = Client(key="EXOtest", secret="wrong_secret")
+        client_with_wrong_key.get_instance(
+            id="85664334-0fd5-47bd-94a1-b4f40b1d2eb7"
+        )
+    except ExoscaleAPIAuthException as e:
+        assert "Authentication error 403" in str(e)
+        assert '{"message":"Invalid request signature"}' in str(e)
+
+    # Mock a 404 client error
+    requests_mock.get(
+        "https://api-ch-gva-2.exoscale.com/v2/instance/85664334-0fd5-47bd-94a1-b4f40b1d2eb7",
+        status_code=404,
+        text='{"message":"Instance not found"}',
+    )
+    try:
+        client.get_instance(id="85664334-0fd5-47bd-94a1-b4f40b1d2eb7")
+    except ExoscaleAPIClientException as e:
+        assert "Client error 404" in str(e)
+        assert '{"message":"Instance not found"}' in str(e)
+
+    # Mock a 500 server error
+    requests_mock.get(
+        "https://api-ch-gva-2.exoscale.com/v2/500_error",
+        status_code=500,
+        text="Internal Server Error",
+    )
+    try:
+        response = client.session.get(
+            "https://api-ch-gva-2.exoscale.com/v2/500_error"
+        )
+        response.raise_for_status()
+    except ExoscaleAPIServerException as e:
+        assert "Server error 500" in str(e)
+    except Exception as e:
+        assert "500 Server Error" in str(e)
+
+
+if __name__ == "__main__":
+    pytest.main()