diff --git a/src/primaite/acl/access_control_list.py b/src/primaite/acl/access_control_list.py
index 9a8444e5..f7e65bd4 100644
--- a/src/primaite/acl/access_control_list.py
+++ b/src/primaite/acl/access_control_list.py
@@ -1,6 +1,6 @@
 # Crown Copyright (C) Dstl 2022. DEFCON 703. Shared in confidence.
 """A class that implements the access control list implementation for the network."""
-from typing import Dict
+from typing import Dict, Optional
 
 from primaite.acl.acl_rule import ACLRule
 
@@ -8,9 +8,9 @@ from primaite.acl.acl_rule import ACLRule
 class AccessControlList:
     """Access Control List class."""
 
-    def __init__(self):
+    def __init__(self) -> None:
         """Initialise an empty AccessControlList."""
-        self.acl: Dict[str, ACLRule] = {}  # A dictionary of ACL Rules
+        self.acl: Dict[int, ACLRule] = {}  # A dictionary of ACL Rules
 
     def check_address_match(self, _rule: ACLRule, _source_ip_address: str, _dest_ip_address: str) -> bool:
         """Checks for IP address matches.
@@ -61,7 +61,7 @@ class AccessControlList:
         # If there has been no rule to allow the IER through, it will return a blocked signal by default
         return True
 
-    def add_rule(self, _permission, _source_ip, _dest_ip, _protocol, _port):
+    def add_rule(self, _permission: str, _source_ip: str, _dest_ip: str, _protocol: str, _port: str) -> None:
         """
         Adds a new rule.
 
@@ -76,7 +76,9 @@ class AccessControlList:
         hash_value = hash(new_rule)
         self.acl[hash_value] = new_rule
 
-    def remove_rule(self, _permission, _source_ip, _dest_ip, _protocol, _port):
+    def remove_rule(
+        self, _permission: str, _source_ip: str, _dest_ip: str, _protocol: str, _port: str
+    ) -> Optional[int]:
         """
         Removes a rule.
 
@@ -95,11 +97,11 @@ class AccessControlList:
         except Exception:
             return
 
-    def remove_all_rules(self):
+    def remove_all_rules(self) -> None:
         """Removes all rules."""
         self.acl.clear()
 
-    def get_dictionary_hash(self, _permission, _source_ip, _dest_ip, _protocol, _port):
+    def get_dictionary_hash(self, _permission: str, _source_ip: str, _dest_ip: str, _protocol: str, _port: str) -> int:
         """
         Produces a hash value for a rule.
 
@@ -117,7 +119,9 @@ class AccessControlList:
         hash_value = hash(rule)
         return hash_value
 
-    def get_relevant_rules(self, _source_ip_address, _dest_ip_address, _protocol, _port):
+    def get_relevant_rules(
+        self, _source_ip_address: str, _dest_ip_address: str, _protocol: str, _port: str
+    ) -> Dict[int, ACLRule]:
         """Get all ACL rules that relate to the given arguments.
 
         :param _source_ip_address: the source IP address to check
@@ -125,9 +129,9 @@ class AccessControlList:
         :param _protocol: the protocol to check
         :param _port: the port to check
         :return: Dictionary of all ACL rules that relate to the given arguments
-        :rtype: Dict[str, ACLRule]
+        :rtype: Dict[int, ACLRule]
         """
-        relevant_rules = {}
+        relevant_rules: Dict[int, ACLRule] = {}
 
         for rule_key, rule_value in self.acl.items():
             if self.check_address_match(rule_value, _source_ip_address, _dest_ip_address):
diff --git a/src/primaite/acl/acl_rule.py b/src/primaite/acl/acl_rule.py
index a1fd93f2..69532376 100644
--- a/src/primaite/acl/acl_rule.py
+++ b/src/primaite/acl/acl_rule.py
@@ -5,7 +5,7 @@
 class ACLRule:
     """Access Control List Rule class."""
 
-    def __init__(self, _permission, _source_ip, _dest_ip, _protocol, _port):
+    def __init__(self, _permission: str, _source_ip: str, _dest_ip: str, _protocol: str, _port: str) -> None:
         """
         Initialise an ACL Rule.
 
@@ -15,13 +15,13 @@ class ACLRule:
         :param _protocol: The rule protocol
         :param _port: The rule port
         """
-        self.permission = _permission
-        self.source_ip = _source_ip
-        self.dest_ip = _dest_ip
-        self.protocol = _protocol
-        self.port = _port
+        self.permission: str = _permission
+        self.source_ip: str = _source_ip
+        self.dest_ip: str = _dest_ip
+        self.protocol: str = _protocol
+        self.port: str = _port
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         """
         Override the hash function.
 
@@ -38,7 +38,7 @@ class ACLRule:
             )
         )
 
-    def get_permission(self):
+    def get_permission(self) -> str:
         """
         Gets the permission attribute.
 
@@ -47,7 +47,7 @@ class ACLRule:
         """
         return self.permission
 
-    def get_source_ip(self):
+    def get_source_ip(self) -> str:
         """
         Gets the source IP address attribute.
 
@@ -56,7 +56,7 @@ class ACLRule:
         """
         return self.source_ip
 
-    def get_dest_ip(self):
+    def get_dest_ip(self) -> str:
         """
         Gets the desintation IP address attribute.
 
@@ -65,7 +65,7 @@ class ACLRule:
         """
         return self.dest_ip
 
-    def get_protocol(self):
+    def get_protocol(self) -> str:
         """
         Gets the protocol attribute.
 
@@ -74,7 +74,7 @@ class ACLRule:
         """
         return self.protocol
 
-    def get_port(self):
+    def get_port(self) -> str:
         """
         Gets the port attribute.