diff --git a/src/Cronofy/ICronofyOAuthClient.cs b/src/Cronofy/ICronofyOAuthClient.cs
index 19e70e8..ad32ec5 100644
--- a/src/Cronofy/ICronofyOAuthClient.cs
+++ b/src/Cronofy/ICronofyOAuthClient.cs
@@ -397,6 +397,18 @@ public interface ICronofyOAuthClient
         /// </exception>
         IAuthorizationUrlBuilder GetEnterpriseConnectAuthorizationUrlBuilder(string redirectUri);
 
+        /// <summary>
+        /// Creates a new attachment that can be added to an event as part of an upsert operation.
+        /// </summary>
+        /// <param name="createAttachmentRequest">
+        /// The details of the attachment to be created.
+        /// </param>
+        /// <returns>
+        /// The created attachment.
+        /// </returns>
+        /// <exception cref="System.ArgumentException">
+        /// Thrown if <paramref name="createAttachmentRequest"/> is null or empty.
+        /// </exception>
         Attachment CreateAttachment(CreateAttachmentRequest createAttachmentRequest);
     }
 }
diff --git a/src/Cronofy/Requests/CreateAttachmentRequest.cs b/src/Cronofy/Requests/CreateAttachmentRequest.cs
index ec94077..05fdcd9 100644
--- a/src/Cronofy/Requests/CreateAttachmentRequest.cs
+++ b/src/Cronofy/Requests/CreateAttachmentRequest.cs
@@ -1,7 +1,7 @@
 namespace Cronofy.Requests
 {
-    using Newtonsoft.Json;
     using System.Collections.Generic;
+    using Newtonsoft.Json;
 
     /// <summary>
     /// Class for the serialization of a create attachment request.
diff --git a/src/Cronofy/Responses/AttachmentResponse.cs b/src/Cronofy/Responses/AttachmentResponse.cs
index ad9d41c..7a762fd 100644
--- a/src/Cronofy/Responses/AttachmentResponse.cs
+++ b/src/Cronofy/Responses/AttachmentResponse.cs
@@ -19,30 +19,61 @@ internal sealed class AttachmentResponse
         [JsonProperty("attachment")]
         public AttachmentSummary Attachment { get; set; }
 
+        /// <summary>
+        /// Converts the response into an attachment.
+        /// </summary>
+        /// <returns>The response as an attachment.</returns>
+        public Attachment ToAttachment()
+        {
+            return new Attachment
+            {
+                AttachmentId = this.Attachment.AttachmentId,
+                FileName = this.Attachment.FileName,
+                ContentType = this.Attachment.ContentType,
+                MD5 = this.Attachment.MD5,
+            };
+        }
+
+        /// <summary>
+        /// Class for the serialization of attachment summary.
+        /// </summary>
         internal sealed class AttachmentSummary
         {
+            /// <summary>
+            /// Gets or sets the id of the attachment.
+            /// </summary>
+            /// <value>
+            /// The id of the attachment.
+            /// </value>
             [JsonProperty("attachment_id")]
             public string AttachmentId { get; set; }
 
+            /// <summary>
+            /// Gets or sets the name of the attachment file.
+            /// </summary>
+            /// <value>
+            /// The name of the attachment file.
+            /// </value>
             [JsonProperty("file_name")]
             public string FileName { get; set; }
 
+            /// <summary>
+            /// Gets or sets the MIME content type of the attachment.
+            /// </summary>
+            /// <value>
+            /// The MIME content type of the attachment.
+            /// </value>
             [JsonProperty("content_type")]
             public string ContentType { get; set; }
 
+            /// <summary>
+            /// Gets or sets the MD5 hash of the attachment file content.
+            /// </summary>
+            /// <value>
+            /// The MD5 hash of the attachment file content.
+            /// </value>
             [JsonProperty("md5")]
             public string MD5 { get; set; }
         }
-
-        public Attachment ToAttachment()
-        {
-            return new Attachment
-            {
-                AttachmentId = this.Attachment.AttachmentId,
-                FileName = this.Attachment.FileName,
-                ContentType = this.Attachment.ContentType,
-                MD5 = this.Attachment.MD5,
-            };
-        }
     }
 }