diff --git a/.stats.yml b/.stats.yml
index 1411d5d..5f2504d 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,2 +1,2 @@
 configured_endpoints: 48
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/metronome%2Fmetronome-d2fa6d063941c7141d1ae74c3d92c7875776087c850dd1ad2d5db0a61679b10e.yml
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/metronome%2Fmetronome-640c4d54c542cc7c00227b484ed677e88fc79dcdf17c526a49615c9ae0500432.yml
diff --git a/src/resources/customers/invoices.ts b/src/resources/customers/invoices.ts
index 3b9856e..73706b0 100644
--- a/src/resources/customers/invoices.ts
+++ b/src/resources/customers/invoices.ts
@@ -314,10 +314,24 @@ export namespace Invoice {
        */
       start_date?: string;
 
+      /**
+       * when the current tier started and ends (for tiered charges only)
+       */
+      tier_period?: SubLineItem.TierPeriod;
+
       tiers?: Array<SubLineItem.Tier>;
     }
 
     export namespace SubLineItem {
+      /**
+       * when the current tier started and ends (for tiered charges only)
+       */
+      export interface TierPeriod {
+        starting_at: string;
+
+        ending_before?: string;
+      }
+
       export interface Tier {
         price: number;
 
diff --git a/src/resources/shared.ts b/src/resources/shared.ts
index cfda1d1..ec3a4aa 100644
--- a/src/resources/shared.ts
+++ b/src/resources/shared.ts
@@ -751,6 +751,8 @@ export interface Rate {
     | 'TIERED'
     | 'tiered';
 
+  credit_type?: CreditType;
+
   /**
    * Only set for CUSTOM rate_type. This field is interpreted by custom rate
    * processors.