diff --git a/docs/source/changelog.rst b/docs/source/changelog.rst
index 7bda4af..1bf7dbc 100644
--- a/docs/source/changelog.rst
+++ b/docs/source/changelog.rst
@@ -1,6 +1,15 @@
 Changelog
 ---------
 
+PyHamTools 0.5.5
+================
+
+18. August 2016
+
+ * Refined callsign detection rule for two digit prefix with appendix (e.g. 7N0ERX/1)
+ * Refined callsign detection rule for callsigns with two appendixes (e.g. SV8GXQ/P/QRP)
+
+
 PyHamTools 0.5.4
 ================
 
diff --git a/pyhamtools/callinfo.py b/pyhamtools/callinfo.py
index 9e37eae..ba03b82 100644
--- a/pyhamtools/callinfo.py
+++ b/pyhamtools/callinfo.py
@@ -136,7 +136,7 @@ class Callinfo(object):
             if re.search('\-\d{1,3}$', entire_callsign):  # cut off any -10 / -02 appendixes
                 callsign = re.sub('\-\d{1,3}$', '', entire_callsign)
 
-            if re.search('/[A-Z0-9]{2,4}/[A-Z0-9]{1,4}$', callsign):
+            if re.search('/[A-Z0-9]{1,4}/[A-Z0-9]{1,4}$', callsign):
                 callsign = re.sub('/[A-Z0-9]{1,4}$', '', callsign)  # cut off 2. appendix DH1TW/HC2/P -> DH1TW/HC2
 
             # multiple character appendix (callsign/xxx)
@@ -199,8 +199,11 @@ class Callinfo(object):
 
                 elif re.search('\d$', appendix):
                     area_nr = re.search('\d$', appendix).group(0)
-                    callsign = re.sub('/\d$', '', callsign)
-                    callsign = re.sub('[\d]+', area_nr, callsign)
+                    callsign = re.sub('/\d$', '', callsign) #remove /number
+                    if len(re.findall(r'\d+', callsign)) == 1: #call has just on digit e.g. DH1TW
+                        callsign = re.sub('[\d]+', area_nr, callsign)
+                    else: # call has several digits e.g. 7N4AAL
+                        pass # no (two) digit prefix contries known where appendix would change entitiy
                     return self._iterate_prefix(callsign, timestamp)
 
                 else:
@@ -231,8 +234,8 @@ class Callinfo(object):
         # Check if operation is invalid
         invalid = False
         try:
-            if self._lookuplib.is_invalid_operation(callsign, timestamp):
-                invalid = True
+            invalid = self._lookuplib.is_invalid_operation(callsign, timestamp)
+            if invalid:
                 raise KeyError
         except KeyError:
             if invalid:
diff --git a/test/test_callinfo.py b/test/test_callinfo.py
index 773399d..a3d044d 100644
--- a/test/test_callinfo.py
+++ b/test/test_callinfo.py
@@ -102,6 +102,23 @@ response_prefix_VK9GMW_clublog = {
     u'longitude': -155.8
 }
 
+response_callsign_exceptions_7N1PRD_0_clublog = {
+    u'adif': 339,
+    u'continent': u'AS',
+    u'country': u'JAPAN',
+    u'cqz': 25,
+    u'latitude': 35.7,
+    u'longitude': -139.8
+}
+
+response_callsign_exceptions_SV8GXQ_P_QRP_clublog = {
+    u'adif': 236,
+    u'continent': u'EU',
+    u'country': u'GREECE',
+    u'cqz': 20,
+    u'latitude': 38.0,
+    u'longitude': -23.7
+}
 
 response_Exception_VP8STI_with_start_and_stop_date = {
            'adif': 240,
@@ -221,6 +238,8 @@ class Test_callinfo_methods:
             assert fix_callinfo._dismantle_callsign("DH1TW/NOT") == response_prefix_DH_clublog
             assert fix_callinfo._dismantle_callsign("VK9DLX/NOT") == response_prefix_VK9DLX_clublog
             assert fix_callinfo._dismantle_callsign("7QAA") == response_callsign_exceptions_7QAA_clublog
+            assert fix_callinfo._dismantle_callsign("7N1PRD/0") == response_callsign_exceptions_7N1PRD_0_clublog
+            assert fix_callinfo._dismantle_callsign("SV8GXQ/P/QRP") == response_callsign_exceptions_SV8GXQ_P_QRP_clublog
 
             with pytest.raises(KeyError):
                 fix_callinfo._dismantle_callsign("OZ/JO85")
diff --git a/test/test_lookuplib_redis.py b/test/test_lookuplib_redis.py
index b1a5b92..7ccdeb0 100644
--- a/test/test_lookuplib_redis.py
+++ b/test/test_lookuplib_redis.py
@@ -5,7 +5,7 @@ from datetime import datetime
 import pytz
 import redis
 
-from pyhamtools import LookupLib
+from pyhamtools import LookupLib, Callinfo
 
 
 UTC = pytz.UTC
@@ -13,6 +13,16 @@ UTC = pytz.UTC
 r = redis.Redis()
 
 
+response_Exception_VP8STI_with_start_and_stop_date = {
+           'adif': 240,
+           'country': u'SOUTH SANDWICH ISLANDS',
+           'continent': u'SA',
+           'latitude': -59.45,
+           'longitude': 27.4,
+           'cqz': 13,
+        }
+
+
 class TestStoreDataInRedis:
 
     def test_copy_data_in_redis(self, fixClublogXML, fix_redis):
@@ -39,4 +49,9 @@ class TestStoreDataInRedis:
         lib = LookupLib(lookuptype="redis", redis_prefix="CF", redis_instance=r)
         fixCountryFile.copy_data_in_redis("CF", r)
         assert lib.lookup_callsign("3D2RI") == fixCountryFile.lookup_callsign("3D2RI")
-        assert lib.lookup_prefix("DH") == fixCountryFile.lookup_prefix("DH")
\ No newline at end of file
+        assert lib.lookup_prefix("DH") == fixCountryFile.lookup_prefix("DH")
+
+    def test_redis_lookup(self, fixClublogXML, fix_redis):
+        timestamp = datetime(year=2016, month=1, day=20, tzinfo=UTC)
+        ci = Callinfo(fix_redis)
+        assert ci.get_all("VP8STI", timestamp) == response_Exception_VP8STI_with_start_and_stop_date