diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index dec47960..d4f0c6a2 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "5.20.0"
+  ".": "5.21.0"
 }
diff --git a/.stats.yml b/.stats.yml
index 320998e1..f2277cfc 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 118
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/orb%2Forb-828c91953d2351040fdd4d90a3d9eafd09f9d240c4f6ce0441b7a10c06c1c722.yml
-openapi_spec_hash: c82bc88563f80f600e59e22014d4cec4
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/orb%2Forb-cbce25283cb9c3282e03e08b7ee81395436af7d0eb480ffcbab307b5bf1c92a0.yml
+openapi_spec_hash: c286edf46db95dee05eb6f180ac24ab0
 config_hash: 1f73a949b649ecfe6ec68ba1bb459dc2
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7bc51ec..d0f2c1d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 5.21.0 (2025-10-23)
+
+Full Changelog: [v5.20.0...v5.21.0](https://github.com/orbcorp/orb-node/compare/v5.20.0...v5.21.0)
+
+### Features
+
+* **api:** api update ([20c99bc](https://github.com/orbcorp/orb-node/commit/20c99bc81d42191d69d38042483b2d3584d416e2))
+
 ## 5.20.0 (2025-10-17)
 
 Full Changelog: [v5.19.0...v5.20.0](https://github.com/orbcorp/orb-node/compare/v5.19.0...v5.20.0)
diff --git a/package.json b/package.json
index f3ed5437..803f5640 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "orb-billing",
-  "version": "5.20.0",
+  "version": "5.21.0",
   "description": "The official TypeScript library for the Orb API",
   "author": "Orb <team@withorb.com>",
   "types": "dist/index.d.ts",
diff --git a/src/resources/subscription-changes.ts b/src/resources/subscription-changes.ts
index 7b4ea301..e93e26c0 100644
--- a/src/resources/subscription-changes.ts
+++ b/src/resources/subscription-changes.ts
@@ -326,6 +326,23 @@ export interface SubscriptionChangeApplyParams {
    */
   mark_as_paid?: boolean | null;
 
+  /**
+   * An optional external ID to associate with the payment. Only applicable when
+   * mark_as_paid is true.
+   */
+  payment_external_id?: string | null;
+
+  /**
+   * Optional notes about the payment. Only applicable when mark_as_paid is true.
+   */
+  payment_notes?: string | null;
+
+  /**
+   * A date string to specify the date the payment was received. Only applicable when
+   * mark_as_paid is true. If not provided, defaults to the current date.
+   */
+  payment_received_date?: string | null;
+
   /**
    * Amount already collected to apply to the customer's balance. If mark_as_paid is
    * also provided, credit the difference to the customer's balance.
diff --git a/src/version.ts b/src/version.ts
index 36168d9b..2d3d2040 100644
--- a/src/version.ts
+++ b/src/version.ts
@@ -1 +1 @@
-export const VERSION = '5.20.0'; // x-release-please-version
+export const VERSION = '5.21.0'; // x-release-please-version
diff --git a/tests/api-resources/subscription-changes.test.ts b/tests/api-resources/subscription-changes.test.ts
index 84a12de9..1f1e2090 100644
--- a/tests/api-resources/subscription-changes.test.ts
+++ b/tests/api-resources/subscription-changes.test.ts
@@ -53,6 +53,9 @@ describe('resource subscriptionChanges', () => {
         {
           description: 'description',
           mark_as_paid: true,
+          payment_external_id: 'payment_external_id',
+          payment_notes: 'payment_notes',
+          payment_received_date: '2019-12-27',
           previously_collected_amount: 'previously_collected_amount',
         },
         { path: '/_stainless_unknown_path' },