diff --git a/lib/recurly/client.php b/lib/recurly/client.php
index 7bb94571..fdff23d2 100644
--- a/lib/recurly/client.php
+++ b/lib/recurly/client.php
@@ -3324,6 +3324,45 @@ public function showExternalInvoice(string $external_invoice_id, array $options
         return $this->makeRequest('GET', $path, [], $options);
     }
   
+    /**
+     * List the external payment phases on an external subscription
+     *
+     * @param string $external_subscription_id External subscription id
+     * @param array  $options                  Associative array of optional parameters
+     *
+     * Supported optional query string parameters:
+     *
+     * - $options['params']['sort'] (string): Sort field. You *really* only want to sort by `updated_at` in ascending
+     *        order. In descending order updated records will move behind the cursor and could
+     *        prevent some records from being returned.
+     * - $options['params']['limit'] (int): Limit number of records 1-200.
+     * - $options['params']['order'] (string): Sort order.
+     *
+     * @return \Recurly\Pager A list of the the external_payment_phases on a site.
+     * @link   https://developers.recurly.com/api/v2021-02-25#operation/list_external_subscription_external_payment_phases
+     */
+    public function listExternalSubscriptionExternalPaymentPhases(string $external_subscription_id, array $options = []): \Recurly\Pager
+    {
+        $path = $this->interpolatePath("/external_subscriptions/{external_subscription_id}/external_payment_phases", ['external_subscription_id' => $external_subscription_id]);
+        return new \Recurly\Pager($this, $path, $options);
+    }
+  
+    /**
+     * Fetch an external payment_phase
+     *
+     * @param string $external_subscription_id  External subscription id
+     * @param string $external_payment_phase_id External payment phase ID, e.g. `a34ypb2ef9w1`.
+     * @param array  $options                   Associative array of optional parameters
+     *
+     * @return \Recurly\Resources\ExternalPaymentPhase Details for an external payment_phase.
+     * @link   https://developers.recurly.com/api/v2021-02-25#operation/get_external_subscription_external_payment_phase
+     */
+    public function getExternalSubscriptionExternalPaymentPhase(string $external_subscription_id, string $external_payment_phase_id, array $options = []): \Recurly\Resources\ExternalPaymentPhase
+    {
+        $path = $this->interpolatePath("/external_subscriptions/{external_subscription_id}/external_payment_phases/{external_payment_phase_id}", ['external_subscription_id' => $external_subscription_id, 'external_payment_phase_id' => $external_payment_phase_id]);
+        return $this->makeRequest('GET', $path, [], $options);
+    }
+  
     /**
      * List entitlements granted to an account
      *
diff --git a/lib/recurly/resources/external_payment_phase.php b/lib/recurly/resources/external_payment_phase.php
new file mode 100644
index 00000000..94100450
--- /dev/null
+++ b/lib/recurly/resources/external_payment_phase.php
@@ -0,0 +1,379 @@
+<?php
+/**
+ * This file is automatically created by Recurly's OpenAPI generation process
+ * and thus any edits you make by hand will be lost. If you wish to make a
+ * change to this file, please create a Github issue explaining the changes you
+ * need and we will usher them to the appropriate places.
+ */
+namespace Recurly\Resources;
+
+use Recurly\RecurlyResource;
+
+// phpcs:disable
+class ExternalPaymentPhase extends RecurlyResource
+{
+    private $_amount;
+    private $_created_at;
+    private $_currency;
+    private $_ending_billing_period_index;
+    private $_ends_at;
+    private $_external_subscription;
+    private $_id;
+    private $_object;
+    private $_offer_name;
+    private $_offer_type;
+    private $_period_count;
+    private $_period_length;
+    private $_started_at;
+    private $_starting_billing_period_index;
+    private $_updated_at;
+
+    protected static $array_hints = [
+    ];
+
+    
+    /**
+    * Getter method for the amount attribute.
+    * Allows up to 9 decimal places
+    *
+    * @return ?string
+    */
+    public function getAmount(): ?string
+    {
+        return $this->_amount;
+    }
+
+    /**
+    * Setter method for the amount attribute.
+    *
+    * @param string $amount
+    *
+    * @return void
+    */
+    public function setAmount(string $amount): void
+    {
+        $this->_amount = $amount;
+    }
+
+    /**
+    * Getter method for the created_at attribute.
+    * When the external subscription was created in Recurly.
+    *
+    * @return ?string
+    */
+    public function getCreatedAt(): ?string
+    {
+        return $this->_created_at;
+    }
+
+    /**
+    * Setter method for the created_at attribute.
+    *
+    * @param string $created_at
+    *
+    * @return void
+    */
+    public function setCreatedAt(string $created_at): void
+    {
+        $this->_created_at = $created_at;
+    }
+
+    /**
+    * Getter method for the currency attribute.
+    * 3-letter ISO 4217 currency code.
+    *
+    * @return ?string
+    */
+    public function getCurrency(): ?string
+    {
+        return $this->_currency;
+    }
+
+    /**
+    * Setter method for the currency attribute.
+    *
+    * @param string $currency
+    *
+    * @return void
+    */
+    public function setCurrency(string $currency): void
+    {
+        $this->_currency = $currency;
+    }
+
+    /**
+    * Getter method for the ending_billing_period_index attribute.
+    * Ending Billing Period Index
+    *
+    * @return ?int
+    */
+    public function getEndingBillingPeriodIndex(): ?int
+    {
+        return $this->_ending_billing_period_index;
+    }
+
+    /**
+    * Setter method for the ending_billing_period_index attribute.
+    *
+    * @param int $ending_billing_period_index
+    *
+    * @return void
+    */
+    public function setEndingBillingPeriodIndex(int $ending_billing_period_index): void
+    {
+        $this->_ending_billing_period_index = $ending_billing_period_index;
+    }
+
+    /**
+    * Getter method for the ends_at attribute.
+    * Ends At
+    *
+    * @return ?string
+    */
+    public function getEndsAt(): ?string
+    {
+        return $this->_ends_at;
+    }
+
+    /**
+    * Setter method for the ends_at attribute.
+    *
+    * @param string $ends_at
+    *
+    * @return void
+    */
+    public function setEndsAt(string $ends_at): void
+    {
+        $this->_ends_at = $ends_at;
+    }
+
+    /**
+    * Getter method for the external_subscription attribute.
+    * Subscription from an external resource such as Apple App Store or Google Play Store.
+    *
+    * @return ?\Recurly\Resources\ExternalSubscription
+    */
+    public function getExternalSubscription(): ?\Recurly\Resources\ExternalSubscription
+    {
+        return $this->_external_subscription;
+    }
+
+    /**
+    * Setter method for the external_subscription attribute.
+    *
+    * @param \Recurly\Resources\ExternalSubscription $external_subscription
+    *
+    * @return void
+    */
+    public function setExternalSubscription(\Recurly\Resources\ExternalSubscription $external_subscription): void
+    {
+        $this->_external_subscription = $external_subscription;
+    }
+
+    /**
+    * Getter method for the id attribute.
+    * System-generated unique identifier for an external payment phase ID, e.g. `e28zov4fw0v2`.
+    *
+    * @return ?string
+    */
+    public function getId(): ?string
+    {
+        return $this->_id;
+    }
+
+    /**
+    * Setter method for the id attribute.
+    *
+    * @param string $id
+    *
+    * @return void
+    */
+    public function setId(string $id): void
+    {
+        $this->_id = $id;
+    }
+
+    /**
+    * Getter method for the object attribute.
+    * Object type
+    *
+    * @return ?string
+    */
+    public function getObject(): ?string
+    {
+        return $this->_object;
+    }
+
+    /**
+    * Setter method for the object attribute.
+    *
+    * @param string $object
+    *
+    * @return void
+    */
+    public function setObject(string $object): void
+    {
+        $this->_object = $object;
+    }
+
+    /**
+    * Getter method for the offer_name attribute.
+    * Name of the discount offer given, e.g. "introductory"
+    *
+    * @return ?string
+    */
+    public function getOfferName(): ?string
+    {
+        return $this->_offer_name;
+    }
+
+    /**
+    * Setter method for the offer_name attribute.
+    *
+    * @param string $offer_name
+    *
+    * @return void
+    */
+    public function setOfferName(string $offer_name): void
+    {
+        $this->_offer_name = $offer_name;
+    }
+
+    /**
+    * Getter method for the offer_type attribute.
+    * Type of discount offer given, e.g. "FREE_TRIAL"
+    *
+    * @return ?string
+    */
+    public function getOfferType(): ?string
+    {
+        return $this->_offer_type;
+    }
+
+    /**
+    * Setter method for the offer_type attribute.
+    *
+    * @param string $offer_type
+    *
+    * @return void
+    */
+    public function setOfferType(string $offer_type): void
+    {
+        $this->_offer_type = $offer_type;
+    }
+
+    /**
+    * Getter method for the period_count attribute.
+    * Number of billing periods
+    *
+    * @return ?int
+    */
+    public function getPeriodCount(): ?int
+    {
+        return $this->_period_count;
+    }
+
+    /**
+    * Setter method for the period_count attribute.
+    *
+    * @param int $period_count
+    *
+    * @return void
+    */
+    public function setPeriodCount(int $period_count): void
+    {
+        $this->_period_count = $period_count;
+    }
+
+    /**
+    * Getter method for the period_length attribute.
+    * Billing cycle length
+    *
+    * @return ?string
+    */
+    public function getPeriodLength(): ?string
+    {
+        return $this->_period_length;
+    }
+
+    /**
+    * Setter method for the period_length attribute.
+    *
+    * @param string $period_length
+    *
+    * @return void
+    */
+    public function setPeriodLength(string $period_length): void
+    {
+        $this->_period_length = $period_length;
+    }
+
+    /**
+    * Getter method for the started_at attribute.
+    * Started At
+    *
+    * @return ?string
+    */
+    public function getStartedAt(): ?string
+    {
+        return $this->_started_at;
+    }
+
+    /**
+    * Setter method for the started_at attribute.
+    *
+    * @param string $started_at
+    *
+    * @return void
+    */
+    public function setStartedAt(string $started_at): void
+    {
+        $this->_started_at = $started_at;
+    }
+
+    /**
+    * Getter method for the starting_billing_period_index attribute.
+    * Starting Billing Period Index
+    *
+    * @return ?int
+    */
+    public function getStartingBillingPeriodIndex(): ?int
+    {
+        return $this->_starting_billing_period_index;
+    }
+
+    /**
+    * Setter method for the starting_billing_period_index attribute.
+    *
+    * @param int $starting_billing_period_index
+    *
+    * @return void
+    */
+    public function setStartingBillingPeriodIndex(int $starting_billing_period_index): void
+    {
+        $this->_starting_billing_period_index = $starting_billing_period_index;
+    }
+
+    /**
+    * Getter method for the updated_at attribute.
+    * When the external subscription was updated in Recurly.
+    *
+    * @return ?string
+    */
+    public function getUpdatedAt(): ?string
+    {
+        return $this->_updated_at;
+    }
+
+    /**
+    * Setter method for the updated_at attribute.
+    *
+    * @param string $updated_at
+    *
+    * @return void
+    */
+    public function setUpdatedAt(string $updated_at): void
+    {
+        $this->_updated_at = $updated_at;
+    }
+}
\ No newline at end of file
diff --git a/lib/recurly/resources/invoice.php b/lib/recurly/resources/invoice.php
index 28b03287..df083cb9 100644
--- a/lib/recurly/resources/invoice.php
+++ b/lib/recurly/resources/invoice.php
@@ -842,7 +842,7 @@ public function setTax(float $tax): void
 
     /**
     * Getter method for the tax_info attribute.
-    * Tax info
+    * Only for merchants using Recurly's In-The-Box taxes.
     *
     * @return ?\Recurly\Resources\TaxInfo
     */
diff --git a/lib/recurly/resources/line_item.php b/lib/recurly/resources/line_item.php
index c0887e91..1e86f217 100644
--- a/lib/recurly/resources/line_item.php
+++ b/lib/recurly/resources/line_item.php
@@ -1136,7 +1136,7 @@ public function setTaxInclusive(bool $tax_inclusive): void
 
     /**
     * Getter method for the tax_info attribute.
-    * Tax info
+    * Only for merchants using Recurly's In-The-Box taxes.
     *
     * @return ?\Recurly\Resources\TaxInfo
     */
diff --git a/lib/recurly/resources/subscription.php b/lib/recurly/resources/subscription.php
index e203593a..4460f1ff 100644
--- a/lib/recurly/resources/subscription.php
+++ b/lib/recurly/resources/subscription.php
@@ -1059,7 +1059,7 @@ public function setSubtotal(float $subtotal): void
 
     /**
     * Getter method for the tax attribute.
-    * Estimated tax
+    * Only for merchants using Recurly's In-The-Box taxes.
     *
     * @return ?float
     */
@@ -1105,7 +1105,7 @@ public function setTaxInclusive(bool $tax_inclusive): void
 
     /**
     * Getter method for the tax_info attribute.
-    * Tax info
+    * Only for merchants using Recurly's In-The-Box taxes.
     *
     * @return ?\Recurly\Resources\TaxInfo
     */
diff --git a/openapi/api.yaml b/openapi/api.yaml
index fe2608a2..c9e015a8 100644
--- a/openapi/api.yaml
+++ b/openapi/api.yaml
@@ -207,6 +207,7 @@ x-tagGroups:
   - external_products
   - external_accounts
   - external_product_references
+  - external_payment_phases
 - name: Products and Promotions
   tags:
   - item
@@ -366,6 +367,11 @@ tags:
   x-displayName: External Product Reference
   description: Associates an external product to a corresponding resource on an external
     platform like the Apple App Store or Google Play Store.
+- name: external_payment_phases
+  x-displayName: External Payment Phase
+  description: Details of payments in the lifecycle of a subscription from an external
+    resource that is not managed by the Recurly platform, e.g. App Store or Google
+    Play Store.
 - name: gift_cards
   x-displayName: Gift Cards
   description: Add gift card purchases to your checkout and allow gift card recipients
@@ -15918,6 +15924,69 @@ paths:
               schema:
                 "$ref": "#/components/schemas/Error"
       x-code-samples: []
+  "/external_subscriptions/{external_subscription_id}/external_payment_phases":
+    parameters:
+    - "$ref": "#/components/parameters/external_subscription_id"
+    get:
+      tags:
+      - external_subscriptions
+      operationId: list_external_subscription_external_payment_phases
+      summary: List the external payment phases on an external subscription
+      description: See the [Pagination Guide](/developers/guides/pagination.html)
+        to learn how to use pagination in the API and Client Libraries.
+      parameters:
+      - "$ref": "#/components/parameters/sort_dates"
+      - "$ref": "#/components/parameters/limit"
+      - "$ref": "#/components/parameters/order"
+      responses:
+        '200':
+          description: A list of the the external_payment_phases on a site.
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/ExternalPaymentPhaseList"
+        '404':
+          description: Incorrect site.
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Error"
+        default:
+          description: Unexpected error.
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Error"
+      x-code-samples: []
+  "/external_subscriptions/{external_subscription_id}/external_payment_phases/{external_payment_phase_id}":
+    parameters:
+    - "$ref": "#/components/parameters/external_subscription_id"
+    - "$ref": "#/components/parameters/external_payment_phase_id"
+    get:
+      tags:
+      - external_payment_phases
+      operationId: get_external_subscription_external_payment_phase
+      summary: Fetch an external payment_phase
+      responses:
+        '200':
+          description: Details for an external payment_phase.
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/ExternalPaymentPhase"
+        '404':
+          description: Incorrect site or external subscription ID.
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Error"
+        default:
+          description: Unexpected error.
+          content:
+            application/json:
+              schema:
+                "$ref": "#/components/schemas/Error"
+      x-code-samples: []
   "/accounts/{account_id}/entitlements":
     parameters:
     - "$ref": "#/components/parameters/account_id"
@@ -16355,6 +16424,13 @@ components:
       required: true
       schema:
         type: string
+    external_payment_phase_id:
+      name: external_payment_phase_id
+      in: path
+      description: External payment phase ID, e.g. `a34ypb2ef9w1`.
+      required: true
+      schema:
+        type: string
     invoice_template_id:
       name: invoice_template_id
       in: path
@@ -21633,6 +21709,7 @@ components:
           type: number
           format: float
           title: Estimated tax
+          description: Only for merchants using Recurly's In-The-Box taxes.
         tax_info:
           "$ref": "#/components/schemas/TaxInfo"
         total:
@@ -22464,6 +22541,12 @@ components:
           default: 0
         net_terms_type:
           "$ref": "#/components/schemas/NetTermsTypeEnum"
+        gateway_code:
+          type: string
+          title: Gateway Code
+          description: If present, this subscription's transactions will use the payment
+            gateway with this code.
+          maxLength: 13
         transaction_type:
           description: An optional type designation for the payment gateway transaction
             created by this request. Supports 'moto' value, which is the acronym for
@@ -22805,6 +22888,7 @@ components:
     TaxInfo:
       type: object
       title: Tax info
+      description: Only for merchants using Recurly's In-The-Box taxes.
       properties:
         type:
           type: string
@@ -23646,6 +23730,90 @@ components:
           type: string
           format: date-time
           description: Time the object was last updated
+    ExternalPaymentPhase:
+      type: object
+      description: Details of payments in the lifecycle of a subscription from an
+        external resource that is not managed by the Recurly platform, e.g. App Store
+        or Google Play Store.
+      properties:
+        id:
+          type: string
+          title: External payment phase ID
+          description: System-generated unique identifier for an external payment
+            phase ID, e.g. `e28zov4fw0v2`.
+        object:
+          type: string
+          title: Object type
+        external_subscription:
+          "$ref": "#/components/schemas/ExternalSubscription"
+        started_at:
+          type: string
+          format: date-time
+          title: Started At
+        ends_at:
+          type: string
+          format: date-time
+          title: Ends At
+        starting_billing_period_index:
+          type: integer
+          title: Starting Billing Period Index
+        ending_billing_period_index:
+          type: integer
+          title: Ending Billing Period Index
+        offer_type:
+          type: string
+          title: Offer Type
+          description: Type of discount offer given, e.g. "FREE_TRIAL"
+        offer_name:
+          type: string
+          title: Offer Name
+          description: Name of the discount offer given, e.g. "introductory"
+        period_count:
+          type: integer
+          title: Period Count
+          description: Number of billing periods
+        period_length:
+          type: string
+          title: Period Length
+          description: Billing cycle length
+        amount:
+          type: string
+          format: decimal
+          title: Amount
+          minimum: 0
+          description: Allows up to 9 decimal places
+        currency:
+          type: string
+          title: Currency
+          description: 3-letter ISO 4217 currency code.
+          maxLength: 3
+        created_at:
+          type: string
+          format: date-time
+          title: Created at
+          description: When the external subscription was created in Recurly.
+        updated_at:
+          type: string
+          format: date-time
+          title: Updated at
+          description: When the external subscription was updated in Recurly.
+    ExternalPaymentPhaseList:
+      type: object
+      properties:
+        object:
+          type: string
+          title: Object type
+          description: Will always be List.
+        has_more:
+          type: boolean
+          description: Indicates there are more results on subsequent pages.
+        next:
+          type: string
+          description: Path to subsequent page of results.
+        data:
+          type: array
+          items:
+            "$ref": "#/components/schemas/ExternalPaymentPhase"
     ExternalProduct:
       type: object
       description: Product from an external resource such as Apple App Store or Google