diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51b67fdd..14508021 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,12 @@
 <!-- This file is generated, please add to it using `knope document-change` in the client-library-templates repo -->
 # Changelog
 
+## 9.9.0 (2026-10-05)
+
+### Features
+
+- Fixed postal_code and country_code fields on Scheme Identifiers to correctly allow null values.
+
 ## 9.8.0 (2026-10-02)
 
 ### Features
diff --git a/README.md b/README.md
index 9b338fbb..144bc44f 100644
--- a/README.md
+++ b/README.md
@@ -14,14 +14,14 @@ With Maven:
 <dependency>
     <groupId>com.gocardless</groupId>
     <artifactId>gocardless-pro</artifactId>
-    <version>9.8.0</version>
+    <version>9.9.0</version>
 </dependency>
 ```
 
 With Gradle:
 
 ```
-implementation 'com.gocardless:gocardless-pro:9.8.0'
+implementation 'com.gocardless:gocardless-pro:9.9.0'
 ```
 
 ## Initializing the client
diff --git a/build.gradle b/build.gradle
index f4149de8..4344533b 100644
--- a/build.gradle
+++ b/build.gradle
@@ -29,7 +29,7 @@ plugins {
 sourceCompatibility = 1.8
 targetCompatibility = 1.8
 group = 'com.gocardless'
-version = '9.8.0'
+version = '9.9.0'
 
 apply plugin: 'ch.raffael.pegdown-doclet'
 
diff --git a/src/main/java/com/gocardless/http/HttpClient.java b/src/main/java/com/gocardless/http/HttpClient.java
index 93acf746..c2bcb4c7 100644
--- a/src/main/java/com/gocardless/http/HttpClient.java
+++ b/src/main/java/com/gocardless/http/HttpClient.java
@@ -35,7 +35,7 @@ public class HttpClient {
     private static final String DISALLOWED_USER_AGENT_CHARACTERS =
             "[^\\w!#$%&'\\*\\+\\-\\.\\^`\\|~]";
     private static final String USER_AGENT =
-            String.format("gocardless-pro-java/9.8.0 java/%s %s/%s %s/%s",
+            String.format("gocardless-pro-java/9.9.0 java/%s %s/%s %s/%s",
                     cleanUserAgentToken(System.getProperty("java.vm.specification.version")),
                     cleanUserAgentToken(System.getProperty("java.vm.name")),
                     cleanUserAgentToken(System.getProperty("java.version")),
@@ -49,7 +49,7 @@ public class HttpClient {
         builder.put("GoCardless-Version", "2015-07-06");
         builder.put("Accept", "application/json");
         builder.put("GoCardless-Client-Library", "gocardless-pro-java");
-        builder.put("GoCardless-Client-Version", "9.8.0");
+        builder.put("GoCardless-Client-Version", "9.9.0");
         HEADERS = builder.build();
     }
     private final OkHttpClient rawClient;