diff --git a/README.rst b/README.rst
index 49d6b43..39359d5 100644
--- a/README.rst
+++ b/README.rst
@@ -132,11 +132,14 @@ v0.6.1
 - Pool plugin now add ``blocked_by_pool`` attribute to session containing elapsed time (seconds) on pool. It allows
   to log this time using log plugins.
 
-- Pool plugin now add ``blocked_by_ratelimit`` attribute to session containing elapsed time (seconds) blocked by
+- RateLimit plugin now add ``blocked_by_ratelimit`` attribute to session containing elapsed time (seconds) blocked by
   rate limit. It allows to log this time using log plugins.
 
 - Tests improved.
 
+- Added new exceptions: :class:`~service_client.plugins.TooManyRequestsPendingError` and
+  :class:`~service_client.plugins.TooMuchTimePendingError`.
+
 - Added decorator in order to help to build service clients. It allows to define a method using a request model
   but to call it using keywords to build request model which will be used to call method.
 
diff --git a/service_client/plugins.py b/service_client/plugins.py
index fb87bf8..99d95ba 100644
--- a/service_client/plugins.py
+++ b/service_client/plugins.py
@@ -318,9 +318,20 @@ class RequestLimitError(Exception):
     pass
 
 
+class TooManyRequestsPendingError(RequestLimitError):
+    pass
+
+
+class TooMuchTimePendingError(RequestLimitError):
+    pass
+
+
 class BaseLimitPlugin(BasePlugin):
     SESSION_ATTR_TIME_BLOCKED = 'blocked'
 
+    TOO_MANY_REQ_PENDING_MSG = "Too many requests pending"
+    TOO_MUCH_TIME_MSG = "Request blocked too much time"
+
     def __init__(self, limit=1, timeout=None, hard_limit=None):
         self.limit = limit
         self._counter = 0
@@ -342,7 +353,7 @@ async def _acquire(self):
                 break
 
             if self._hard_limit is not None and self._hard_limit < self.pending:
-                raise RequestLimitError("Too many requests pending")
+                raise TooManyRequestsPendingError(self.TOO_MANY_REQ_PENDING_MSG)
 
             if self._fut is None:
                 self._fut = self.service_client.loop.create_future()
@@ -356,7 +367,7 @@ async def _acquire(self):
                     if timeout <= 0:
                         raise TimeoutError()
             except TimeoutError:
-                raise RequestLimitError("Request blocked too much time")
+                raise TooMuchTimePendingError(self.TOO_MUCH_TIME_MSG)
             finally:
                 self._pending -= 1
 
@@ -383,6 +394,9 @@ def close(self):
 class Pool(BaseLimitPlugin):
     SESSION_ATTR_TIME_BLOCKED = 'blocked_by_pool'
 
+    TOO_MANY_REQ_PENDING_MSG = "Too many requests pending on pool"
+    TOO_MUCH_TIME_MSG = "Request blocked too much time on pool"
+
     async def on_response(self, endpoint_desc, session, request_params, response):
         self._release()
 
@@ -394,6 +408,9 @@ async def on_exception(self, endpoint_desc, session, request_params, ex):
 class RateLimit(BaseLimitPlugin):
     SESSION_ATTR_TIME_BLOCKED = 'blocked_by_ratelimit'
 
+    TOO_MANY_REQ_PENDING_MSG = "Too many requests pending by rate limit"
+    TOO_MUCH_TIME_MSG = "Request blocked too much time by rate limit"
+
     def __init__(self, period=1, *args, **kwargs):
         super(RateLimit, self).__init__(*args, **kwargs)
         self.period = period
diff --git a/service_client/utils.py b/service_client/utils.py
index 0cf2af2..1566e04 100644
--- a/service_client/utils.py
+++ b/service_client/utils.py
@@ -53,6 +53,7 @@ def random_token(length=10):
 
 
 class ObjectWrapper:
+
     def __init__(self, obj):
         self.__dict__['_obj'] = None
         self.__dict__['_data'] = {}
diff --git a/tests/tests_plugins.py b/tests/tests_plugins.py
index 075e802..90168b2 100644
--- a/tests/tests_plugins.py
+++ b/tests/tests_plugins.py
@@ -17,7 +17,7 @@
 
 from service_client import ConnectionClosedError
 from service_client.plugins import PathTokens, Timeout, Headers, QueryParams, Elapsed, InnerLogger, OuterLogger, \
-    TrackingToken, Pool, RequestLimitError, RateLimit
+    TrackingToken, Pool, RateLimit, TooMuchTimePendingError, TooManyRequestsPendingError
 from service_client.utils import ObjectWrapper
 
 
@@ -1022,7 +1022,7 @@ async def test_timeout(self):
         await self.plugin.before_request(self.endpoint_desc, self.session,
                                          self.request_params)
 
-        with self.assertRaisesRegex(RequestLimitError, "Request blocked too much time"):
+        with self.assertRaisesRegex(TooMuchTimePendingError, "Request blocked too much time on pool"):
             await self.plugin.before_request(self.endpoint_desc, self.session,
                                              self.request_params)
 
@@ -1037,7 +1037,7 @@ async def test_hard_limit(self):
         asyncio.ensure_future(self.plugin.before_request(self.endpoint_desc, self.session,
                                                          self.request_params))
 
-        with self.assertRaisesRegex(RequestLimitError, "Too many requests pending"):
+        with self.assertRaisesRegex(TooManyRequestsPendingError, "Too many requests pending on pool"):
             await asyncio.wait_for(self.plugin.before_request(self.endpoint_desc, self.session,
                                                               self.request_params), timeout=1)
 
@@ -1160,7 +1160,7 @@ async def test_timeout(self):
         await self.plugin.before_request(self.endpoint_desc, self.session,
                                          self.request_params)
 
-        with self.assertRaisesRegex(RequestLimitError, "Request blocked too much time"):
+        with self.assertRaisesRegex(TooMuchTimePendingError, "Request blocked too much time by rate limit"):
             await self.plugin.before_request(self.endpoint_desc, self.session,
                                              self.request_params)
 
@@ -1175,7 +1175,7 @@ async def test_hard_limit(self):
         asyncio.ensure_future(self.plugin.before_request(self.endpoint_desc, self.session,
                                                          self.request_params))
 
-        with self.assertRaisesRegex(RequestLimitError, "Too many requests pending"):
+        with self.assertRaisesRegex(TooManyRequestsPendingError, "Too many requests pending by rate limit"):
             await asyncio.wait_for(self.plugin.before_request(self.endpoint_desc, self.session,
                                                               self.request_params), timeout=1)