diff --git a/src/Intercom.Tests/Core/ClientTest.cs b/src/Intercom.Tests/Core/ClientTest.cs
index 86ae70a..d998496 100755
--- a/src/Intercom.Tests/Core/ClientTest.cs
+++ b/src/Intercom.Tests/Core/ClientTest.cs
@@ -1,13 +1,49 @@
-using NUnit.Framework;
+using System;
+using System.IO;
+using Intercom.Clients;
+using Intercom.Core;
+using Intercom.Exceptions;
+using Intercom.Factories;
+using Moq;
+using NUnit.Framework;
+using RestSharp;
 
 namespace Intercom.Test
 {
     [TestFixture ()]
     public class ClientTest
     {
+        private static IRestRequest CaptureRequest(Action<ContactsClient> call)
+        {
+            IRestRequest captured = null;
+            var restClient = new Mock<IRestClient>();
+            restClient.Setup(_ => _.Execute(It.IsAny<IRestRequest>()))
+                .Callback<IRestRequest>(r => captured = r)
+                .Returns((IRestResponse)null);
+            var factory = new Mock<RestClientFactory>(new Authentication("DEFAULT", "DEFAULT"));
+            factory.Setup(_ => _.RestClient).Returns(restClient.Object);
+
+            try { call(new ContactsClient(factory.Object)); }
+            catch (IntercomException) { }
+
+            return captured;
+        }
+
         [Test]
-        public void Test ()
+        public void EncodesIdWhenBuildingPath ()
+        {
+            var request = CaptureRequest(c => c.View("a/b?x=1#f"));
+
+            var uri = new RestClient("https://api.intercom.io/").BuildUri(request);
+            Assert.AreEqual("/contacts/a%2Fb%3Fx%3D1%23f", uri.AbsolutePath);
+            Assert.AreEqual(String.Empty, uri.Query);
+        }
+
+        [TestCase(".")]
+        [TestCase("..")]
+        public void RejectsDotSegmentId (string id)
         {
+            Assert.Throws<ArgumentException>(() => CaptureRequest(c => c.View(id)));
         }
     }
 }
\ No newline at end of file
diff --git a/src/Intercom/Clients/AdminConversationsClient.cs b/src/Intercom/Clients/AdminConversationsClient.cs
index 4316288..ed36408 100644
--- a/src/Intercom/Clients/AdminConversationsClient.cs
+++ b/src/Intercom/Clients/AdminConversationsClient.cs
@@ -44,7 +44,7 @@ public Conversation Reply(AdminConversationReply reply)
 
             ClientResponse<Conversation> result = null;
             String body = Serialize<AdminConversationReply>(reply);
-            result = Post<Conversation>(body, resource: CONVERSATIONS_RESOURCE + Path.DirectorySeparatorChar + reply.conversation_id + Path.DirectorySeparatorChar + REPLY_RESOURCE);
+            result = Post<Conversation>(body, resource: CONVERSATIONS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(reply.conversation_id) + Path.DirectorySeparatorChar + REPLY_RESOURCE);
             return result.Result;
         }
 
diff --git a/src/Intercom/Clients/AdminsClient.cs b/src/Intercom/Clients/AdminsClient.cs
index cc82fb2..a0dd3c0 100644
--- a/src/Intercom/Clients/AdminsClient.cs
+++ b/src/Intercom/Clients/AdminsClient.cs
@@ -65,7 +65,7 @@ public Admin View (String id)
             }
 
             ClientResponse<Admin> result = null;
-            result = Get<Admin> (resource: ADMINS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Admin> (resource: ADMINS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
@@ -81,7 +81,7 @@ public Admin View(Admin admin)
             }
 
             ClientResponse<Admin> result = null;
-            result = Get<Admin> (resource: ADMINS_RESOURCE + Path.DirectorySeparatorChar + admin.id);
+            result = Get<Admin> (resource: ADMINS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(admin.id));
             return result.Result;  
         }
     }
diff --git a/src/Intercom/Clients/CompanyClient.cs b/src/Intercom/Clients/CompanyClient.cs
index b004fdb..71ef0cb 100644
--- a/src/Intercom/Clients/CompanyClient.cs
+++ b/src/Intercom/Clients/CompanyClient.cs
@@ -78,7 +78,7 @@ public Company View(String id)
                 throw new ArgumentNullException(nameof(id));
             }
             ClientResponse<Company> result = null;
-            result = Get<Company>(resource: COMPANIES_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Company>(resource: COMPANIES_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
@@ -94,7 +94,7 @@ public Company View(Company company)
 
             if (!String.IsNullOrEmpty(company.id))
             {
-                result = Get<Company>(resource: COMPANIES_RESOURCE + Path.DirectorySeparatorChar + company.id);
+                result = Get<Company>(resource: COMPANIES_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(company.id));
             }
             else if (!String.IsNullOrEmpty(company.name))
             {
@@ -163,7 +163,7 @@ public Users ListUsers(Company company)
 
             if (!String.IsNullOrEmpty(company.id))
             {
-                String resource = company.id + Path.DirectorySeparatorChar + "users";
+                String resource = EncodePathSegment(company.id) + Path.DirectorySeparatorChar + "users";
                 result = Get<Users>(resource: COMPANIES_RESOURCE + Path.DirectorySeparatorChar + resource);
             }
             else if (!String.IsNullOrEmpty(company.company_id))
@@ -187,7 +187,7 @@ public Users ListUsers(String companyId)
                 throw new ArgumentNullException(nameof(companyId));
             }
 
-            String resource = companyId + Path.DirectorySeparatorChar + "users";
+            String resource = EncodePathSegment(companyId) + Path.DirectorySeparatorChar + "users";
             ClientResponse<Users> result = null;
             result = Get<Users>(resource: COMPANIES_RESOURCE + Path.DirectorySeparatorChar + resource);
             return result.Result;
diff --git a/src/Intercom/Clients/ContactsClient.cs b/src/Intercom/Clients/ContactsClient.cs
index a523066..8f04a4c 100644
--- a/src/Intercom/Clients/ContactsClient.cs
+++ b/src/Intercom/Clients/ContactsClient.cs
@@ -76,7 +76,7 @@ public Contact View (String id)
             }
 
             ClientResponse<Contact> result = null;
-            result = Get<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;       
         }
 
@@ -90,7 +90,7 @@ public Contact View (Contact contact)
             ClientResponse<Contact> result = null;
 
             if (!String.IsNullOrEmpty (contact.id)) {
-                result = Get<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + contact.id);
+                result = Get<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(contact.id));
             } else if (!String.IsNullOrEmpty (contact.user_id)) {
                 parameters.Add (Constants.USER_ID, contact.user_id);
                 result = Get<Contact> (parameters: parameters);
@@ -162,7 +162,7 @@ public Contact Delete (Contact contact)
             ClientResponse<Contact> result = null;
 
             if (!String.IsNullOrEmpty (contact.id)) {
-                result = Delete<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + contact.id);
+                result = Delete<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(contact.id));
             } else if (!String.IsNullOrEmpty (contact.user_id)) {
                 parameters.Add (Constants.USER_ID, contact.user_id);
                 result = Delete<Contact> (parameters: parameters);
@@ -180,7 +180,7 @@ public Contact Delete (String id)
             }
 
             ClientResponse<Contact> result = null;
-            result = Delete<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Delete<Contact> (resource: CONTACTS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
diff --git a/src/Intercom/Clients/ConversationsClient.cs b/src/Intercom/Clients/ConversationsClient.cs
index bcfcf97..5037084 100644
--- a/src/Intercom/Clients/ConversationsClient.cs
+++ b/src/Intercom/Clients/ConversationsClient.cs
@@ -57,7 +57,7 @@ public Conversation View(String id, bool? displayAsPlainText = null)
             }
 
             ClientResponse<Conversation> result = null;
-            result = Get<Conversation>(resource: CONVERSATIONS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Conversation>(resource: CONVERSATIONS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
diff --git a/src/Intercom/Clients/NotesClient.cs b/src/Intercom/Clients/NotesClient.cs
index 793ddf3..070e794 100644
--- a/src/Intercom/Clients/NotesClient.cs
+++ b/src/Intercom/Clients/NotesClient.cs
@@ -143,7 +143,7 @@ public Note View(String id)
             }
 
             ClientResponse<Note> result = null;
-            result = Get<Note>(resource: NOTES_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Note>(resource: NOTES_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;       
         }
 
diff --git a/src/Intercom/Clients/SegmentsClient.cs b/src/Intercom/Clients/SegmentsClient.cs
index fd84336..f6011ec 100644
--- a/src/Intercom/Clients/SegmentsClient.cs
+++ b/src/Intercom/Clients/SegmentsClient.cs
@@ -81,7 +81,7 @@ public Segment View(String id, bool? includeCount = null)
             };
 
             ClientResponse<Segment> result = null;
-            result = Get<Segment>(parameters: parameters, resource: SEGMENTS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Segment>(parameters: parameters, resource: SEGMENTS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
@@ -104,7 +104,7 @@ public Segment View(Segment segment, bool? includeCount = null)
             };
 
             ClientResponse<Segment> result = null;
-            result = Get<Segment>(parameters: parameters, resource: SEGMENTS_RESOURCE + Path.DirectorySeparatorChar + segment.id);
+            result = Get<Segment>(parameters: parameters, resource: SEGMENTS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(segment.id));
             return result.Result;  
         }
     }
diff --git a/src/Intercom/Clients/TagsClient.cs b/src/Intercom/Clients/TagsClient.cs
index 68a27e8..6c9f7b4 100644
--- a/src/Intercom/Clients/TagsClient.cs
+++ b/src/Intercom/Clients/TagsClient.cs
@@ -83,7 +83,7 @@ public Tag View(String id)
             }
 
             ClientResponse<Tag> result = null;
-            result = Get<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
@@ -98,7 +98,7 @@ public Tag View(Tag tag)
 
             if (!String.IsNullOrEmpty(tag.id))
             {
-                result = Get<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + tag.id);
+                result = Get<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(tag.id));
             }
             else
             {
@@ -144,7 +144,7 @@ public void Delete(Tag tag)
                 throw new ArgumentException("you need to provide 'tag.id' to delete a tag.");
             }
 
-            Delete<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + tag.id);
+            Delete<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(tag.id));
         }
 
         public void Delete(String id)
@@ -154,7 +154,7 @@ public void Delete(String id)
                 throw new ArgumentNullException(nameof(id));
             }
 
-            Delete<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + id);
+            Delete<Tag>(resource: TAGS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
         }
 
         public Tag Tag(String name, List<Company> companies)
diff --git a/src/Intercom/Clients/UserConversationsClient.cs b/src/Intercom/Clients/UserConversationsClient.cs
index ed31e2d..d9223f8 100644
--- a/src/Intercom/Clients/UserConversationsClient.cs
+++ b/src/Intercom/Clients/UserConversationsClient.cs
@@ -45,7 +45,7 @@ public Conversation Reply(UserConversationReply reply)
 
             ClientResponse<Conversation> result = null;
             String body = Serialize<UserConversationReply>(reply);
-            result = Post<Conversation>(body, resource: CONVERSATIONS_RESOURCE + Path.DirectorySeparatorChar + reply.conversation_id + Path.DirectorySeparatorChar + REPLY_RESOURCE);
+            result = Post<Conversation>(body, resource: CONVERSATIONS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(reply.conversation_id) + Path.DirectorySeparatorChar + REPLY_RESOURCE);
             return result.Result;
         }
 
diff --git a/src/Intercom/Clients/UsersClient.cs b/src/Intercom/Clients/UsersClient.cs
index d2a1d23..b84c08b 100644
--- a/src/Intercom/Clients/UsersClient.cs
+++ b/src/Intercom/Clients/UsersClient.cs
@@ -129,7 +129,7 @@ public User View(String id)
             }
 
             ClientResponse<User> result = null;
-            result = Get<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
@@ -145,7 +145,7 @@ public User View(User user)
 
             if (!String.IsNullOrEmpty(user.id))
             {
-                result = Get<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + user.id);
+                result = Get<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(user.id));
             }
             else if (!String.IsNullOrEmpty(user.user_id))
             {
@@ -217,7 +217,7 @@ public User Archive(User user)
 
             if (!String.IsNullOrEmpty(user.id))
             {
-                result = Delete<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + user.id);
+                result = Delete<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(user.id));
             }
             else if (!String.IsNullOrEmpty(user.user_id))
             {
@@ -251,7 +251,7 @@ public User Archive(String id)
             }
 
             ClientResponse<User> result = null;
-            result = Delete<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Delete<User>(resource: USERS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;
         }
 
diff --git a/src/Intercom/Clients/VisitorsClient.cs b/src/Intercom/Clients/VisitorsClient.cs
index c9aa526..c597525 100644
--- a/src/Intercom/Clients/VisitorsClient.cs
+++ b/src/Intercom/Clients/VisitorsClient.cs
@@ -62,7 +62,7 @@ public Visitor View(String id)
             }
 
             ClientResponse<Visitor> result = null;
-            result = Get<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Get<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;       
         }
 
@@ -78,7 +78,7 @@ public Visitor View(Visitor visitor)
 
             if (!String.IsNullOrEmpty(visitor.id))
             {
-                result = Get<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + visitor.id);
+                result = Get<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(visitor.id));
             }
             else if (!String.IsNullOrEmpty(visitor.user_id))
             {
@@ -124,7 +124,7 @@ public Visitor Delete(Visitor visitor)
 
             Dictionary<String, String> parameters = new Dictionary<string, string>();
             ClientResponse<Visitor> result = null;
-            result = Delete<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + visitor.id);
+            result = Delete<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(visitor.id));
             return result.Result;       
         }
 
@@ -136,7 +136,7 @@ public Visitor Delete(String id)
             }
 
             ClientResponse<Visitor> result = null;
-            result = Delete<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + id);
+            result = Delete<Visitor>(resource: VISITORS_RESOURCE + Path.DirectorySeparatorChar + EncodePathSegment(id));
             return result.Result;           
         }
 
diff --git a/src/Intercom/Core/Client.cs b/src/Intercom/Core/Client.cs
index c714126..3d208e3 100644
--- a/src/Intercom/Core/Client.cs
+++ b/src/Intercom/Core/Client.cs
@@ -310,6 +310,14 @@ protected virtual IRestRequest BuildRequest(Method httpMethod = Method.GET,
             return request;
         }
 
+        protected static String EncodePathSegment(String id)
+        {
+            if (String.IsNullOrEmpty(id) || id == "." || id == "..")
+                throw new ArgumentException("The id cannot be used as a path segment.", nameof(id));
+
+            return Uri.EscapeDataString(id);
+        }
+
         protected virtual IRestClient BuildClient()
         {
             return _restClientFactory.RestClient;